Amendment: When purchasing brake levers for cantelever brakes, MAKE SURE it says cantelever brake compatibility in the product description; if it does not, they are only compatible with V Brakes, no matter what the Internet may say. Some Shimano products will work for both by having different...
If it is not clicking, it is because the ratchet pawl is stuck due to old grease. There are two. Douse with degreaser or WD-40 if you do not have any degreaser, let it sit for a few minutes, then work the pawls until they move freely. They have tiny springs of a similar size to what you might...
Got the same model bike in green and did a similar conversion. Used an angled stem extension to bring bars higher. Had to replace brake levers and shifters as shifters were clogged with old grease, and the ratchets no longer worked. Fortunately, I was able to find cheap replacements on Ali...