Looking for ones that clamp on the outside and allow room for the bar-end friction shifters.
Would cross-top types work?
@Coxy I found some Dia Compe levers on SJS which happily mount near the bar ends in which some Ultegra friction/eight-speed-indexed shifters have been plugged. The shifters were a little too fat for a Charge Slice but fit nicely in a Zenith horn-bar (and in the upturned chopped-off drops I tested the arrangement with). Various road-drop-style levers from the Bike Station's brake lever drawer were too bulky in that position. There are a couple of similar things also on SJS but the ones I bought have a little channel at the rear to allow them to almost abut the bar-end shifter's cable exit point.