I've got an old Trek mountain bike (from the 90s) that has a broken right (back) shifter, and I think the front shifter is bad also. It has a Shimano Deore LX shifter set (3x/7x) and CANTILEVER brakes. I'd like to fix it for as little as possible. Anyway, I was a shifter/brake lever combo set (shimano EF-51) on Amazon for about $30 that has rave reviews, but... it is for a V-brake. I think with my cantilever brakes, the v-brake levers won't give much braking power? Am I right and would this be a mistake? Looking at the current brake lever/shifter combo on my Trek, I'm not sure if I can remove just the shifter? And would the EF-51 then attach ok? Any good ideas on a low-cost solution?