Wild theory here, but a look at the still-available SL-MC40 levers
appear to have a similar attachment point of the pods to the bar clamp
as the ST-M560 levers have. Anybody ever tried this, to see if they'll
bolt on?
The other option is to get some ST-EF50s for 3x7/Cantilevers, which
are cheap enough to be sure, but it would be nice if he could keep his
current brake levers.
We strung up some ST-EF50s to replace gripshifts on D.'s Cannondale a
couple weeks ago. Yes they're cheap, but fantastic for anything but
the grimmest trail usage. The integrated lever looks a little fromage,
probably due to the plasticky presentation of the unit's top cap--but
it's solid. They come with all the cables, housings, and ferrules you
need--and throw in the levers for free. I like them better than the
Tiagra/LX pods, TBQPH--despite the lack of front trim. (Set up right
on 7-8 speed, you can live w/o trim)