GP Chain Case for SX150 Engine ?

Advice please ?
Trying to finish a re-build of an old SX150 Innocenti Case ID 22-01-0061, Engine Number starts 2128** so from what I can gather is a 1970 GP 150 frame / SX150 engine ?
I have a SIL Chain case, 22-01-0504 which as far as I can work out is a GP chaincase cover ? Will it fit / work and would I have to make any modifications, do any grinding ? (Ive got it to actually sit on all the studs but not sure if kick start, or clutch etc will all work happily, or I need to mess with certain parts . .
Thanks .
Trying to finish a re-build of an old SX150 Innocenti Case ID 22-01-0061, Engine Number starts 2128** so from what I can gather is a 1970 GP 150 frame / SX150 engine ?
I have a SIL Chain case, 22-01-0504 which as far as I can work out is a GP chaincase cover ? Will it fit / work and would I have to make any modifications, do any grinding ? (Ive got it to actually sit on all the studs but not sure if kick start, or clutch etc will all work happily, or I need to mess with certain parts . .
Thanks .