So Mrs G has a rather nice city bike with 7-speed Shimano Nexus hub gears with a roller brake, Shimano dynamo (with a roller brake, and installed by @Harts Cyclery). She doesn't ride it any more, due to the arrival of the e-bike.
I have a very tired commuter bike (also hub geared with eccentric bottom bracket) and with hydraulic disc brakes that I expect are now defective after a year of not using the bike.
I am minded, partly just because it would be an interesting project, to swap the wheels from Mrs G's bike to mine. I'd need a few cheapish components (new cables and outers, new brake levers, new shifter). The main blocker is the brakes: they need something to hold the reaction arm that makes them work. Mrs G's bike has braze-ons, as does my Elephant Bike. My aim is just to nick the wheels from her bike, rather than plunder it for components...
Does anyone have any experience of installing Shimano roller brakes on a bike that doesn't have the fitting (particularly on the front) to constrain the reaction arm (the fitting on the back is a screw-on bracket).
https://www.sheldonbrown.com/rollerbrakes.html hasn't identified a solution...