OP here - I just want my back-up bike (which is my only bike for this week) to be more usable! I had hoped to do it without spending a lot of time or money. The $50 shifters referenced might work no better than my current shift levers - I had this problem when the bike was new. The Shimano shifters I linked to were the first ones I found when I did a Google search - I thought they looked very, very cheesy. I searched eBay - 105 Shimano shifters like
these? Even though they're "indexed"? Will they have better friction?
Gee, I feel like a monster! But I just am not enough of a vintage fan. I actually prefer riding my CF bike with STI 10 speeds and real brakes. I can easily shift gears and dial them in so I keep my cadence in my target range. I've ridden the Lotus about 500 miles in the two months I've been cycling (vs. about 700 on the 2007 bike) - my only issues with the Lotus are the brakes and the shifting, but those really are pretty big issues of safety and efficiency.
[I have another thread about improving the brakes.]
I did dismantle the shift lever assembly on the down tube and cleaned out the "powder" - I will find out tomorrow if it worked. Depending on how that goes, I will probably experiment with greasing the friction washers. Meantime I guess I can resign myself to knowing that I now know more about the shifting problem and can probably fine-tune my skill at dialing in the tension on the bails - maybe even "wiring" the bails with safety wire so they can't loosen from vibration and normal shifting action.
Thank you all for your suggestions.
PS - I have braze-on bosses.