Thanks for the advice, all. I'll have to try some suggestions out and cross my fingers!
By the way, Pdeeh, do you always run into bad scuffs on Lucky? My batch is OK, though I suspect my rolls were made by the seller from bulk stock, as they have no frame numbers on the negs, and some of the canisters have been overbranded with stickers (the roll I used most recently had the original markings on the canister as being for Lucky 200 C41 - didn't know that type even existed!)