Here's my writeup. Not quite "months behind schedule", but getting there.
The plan was to cycle or walk across as many of the bridges spanning the River Forth as possible in one weekend. On the first day, I'd walk across the new Queensferry Crossing, then cycle to Doune, where I had booked a B&B. On the second day, I'd cycle up to to the source of the Forth at Aberfoyle and then return to Inverkeithing, where I'd get on a train to Edinburgh to cross one more bridge.
Day 1
Our Queensferry crossing time was 3:20pm. We cycled along the canal from Meggetland to Hermiston P&R, which was our allocated travel hub. Nothing noteworthy on the way, but that "Slateford Snake" will be very useful if it comes into existence.
The Queensferry Crossing Experience (Bridge #1) ran very smoothly - we were taken by bus to the south side of the bridge, walked across the bridge at our own pace and then a bus took us from the north side back to Hermiston. The weather co-operated and we crossed the bridge in just under an hour. I was aiming to make it to my B&B in Doune by half past eight, when the kitchen closed, so we didn't faff around too much on the bridge.
It was just after 5pm when I Left Hermiston just after 5pm, and took Gogar Station Road to the A8, then went via Winchburgh and Linlithgow to Grangemouth. First time I've been down Gogar Station Road - it's fantastic! I was mainly keeping head down and trying to get to Doune by half past eight, but without putting in so much effort that I wouldn't survive Day 2. Spotted a dead buzzard in a field near Grangemouth :(
Bridge #2 was also the final one of Day 1 - the Clackmannanshire Bridge. It's rather pleasant to cycle across, with a wide cycle path. On the north side, I crossed from Fife into Clackmannanshire, then made my way along the back roads to Bridge of Allan and eventually Doune.
The midges came out around half past seven, which made the last stretch less fun, but I also came face to face with two different fawns in between Bridge of Allan and Doune.
Didn't quite make it to the B&B by half past eight, and the kitchen had indeed closed. But they were able to give me a plate of soup and a couple of pints of 80 shilling.
Day 2
Big breakfast in the B&B (Woodside Hotel, I should say), and back on the road by half past eight. Bit chilly early doors, and was wishing I'd brought some longer sleeves, but soon warmed up. The A84 south was fairly quiet, and I made good time to Kippen. I took the B-road detour to Kippen in order to minimise time on the main roads, but at that time on a Sunday morning it wasn't really necessary (and if I'd known Kippen was up a hill I wouldn't have bothered).
I crossed the first Forth bridge of Day 2 (Bridge #3), near Gargunnock, without even realising it.
More back roads and Bridge #4 past Monteith/Inchmahome, where I startled a heron, and then into Aberfoyle.
I went up to Loch Ard, took a couple of photos, then turned for home. Bridge #5 was the old stone bridge just east of Loch Ard, which I crossed, then crossed back again to take the main road back to Aberfoyle. Turned right before entering the town centre, and crossed Bridge #6 at Kirkton. Some off-road paths round Doon Hill took me to Bridge #7. After crossing, I briefly followed an NCN 7 cycle path south, parallel to the main road. Crossed Bridge #8, then doubled back to the main road to cross Bridge #9. Turning right, more off-road paths (including a short stretch of slate!) along the old Aberfoyle-Buchylvie railway line, which has a fairly new wooden footbridge (Bridge #10) about halfway to Buchylvie.. This Aberfoyle-Buchlyvie stretch was definitely not designed for road bikes, and I was counting myself lucky to get through it without a puncture.
From Buchylvie, I took the main road east. Managed to miss the turn off to Bridge #11, which is about a mile down a farm track just past the turn off to Kippen. Doubled back, found my way again, and crossed the bridge. A collie barked at me a few times, but she turned out to be incredibly friendly. I doubt she gets many visits from cyclists.
This time I took the main road on the way east, rather than the uphill detour to Kippen, then the back roads (and Bridge #12 on the B822) to Stirling.
Just before Stirling, I crossed the old bridge (Bridge #13) beside the A84, then doubled back to cross the A84 bridge (Bridge #14), and then doubled back again to cross the old bridge again. Crossing the A84 beside Dobbie's wasn't particularly fun, but I was only on it for 100m or so, before turning off to cross under the M9 (Bridge #15). Locked my bike to a railing and walked across the footbridge/pipeline (Bridge #16) beside the M9 bridge.
Through the Raploch, across Stirling Bridge (Bridge #17), then doubled back to cross the A9 bridge (Bridge #18), then crossed under both rail bridges (Bridges #19 and #20). Got a coffee, some cake and refilled water bottles in the Italian café near the train station.
Bridge #21 was the footbridge to Cambuskenneth. I then had to go down the A91 dual carriageway (and Bridge #22), which wasn't as bad as I'd feared, as it has a fairly wide shoulder. I certainly wouldn't like to go down it regularly, though, and was glad to not be turning right at the roundabouts.
From there, I mainly followed NCN 76 again. This is a truly fantastic route in parts, but also has some less-than-fantastic stretches (mainly where it follows farm tracks, but there is also a really nasty gate just north of Cowie, which I struggled to get my perfectly normal bike through).
Bridge #23 was the Kincardine Bridge, which is slightly less pleasant than the Clackmannanshire, since it has a couple of narrow points, and I got lost finding my way back on to NCN 76 at the north end.
Took NCN 76 along the north side of the Firth, stopping to finish my sandwiches and snacks in Culross.
That wee hill on NCN 76, just east of Limekilns, is a right scunner after 250km of cycling, by the way.
Got very lost trying to find my way onto the FRB. No hint at all that the western footway is closed until you're almost at it, then a severe lack of diversion signs guiding you to the east side. Lots of waiting at toucan crossings too.
Crossed the FRB (Bridge #24) in both directions, and made it to Inverkeithing just as a train was pulling in, so I didn't have time to buy a ticket before boarding. And no one came to sell me one, so the train journey over Bridge #25 was free!
I then had possibly my slowest journey ever home from Waverley. Snails would have overtaken me going up Market Street.
Total distance for the weekend ended up being 265 km (165 miles). Fair chuffed with that.