it’ll never work…
“sorry, [shimano component A] definitely won’t work with [shimano component B], you’ll have to get [shimano components C,D,E,F,G,H,I and J]”
This has happened to me so many times and now i just ignore it. most of ’em seem to be compatible to me, maybe my threshold is a bit low 🙂
Also, what’s with bike shops wanting to replace seized mechs every time they seize? the number of friends who’ve asked me if i have a spare one because the bike shop said they needed a new one. just oil it and jiggle it about a bit. it’ll be fine!