My RC600 when found due to old age and damp storage had the rubber bonded to the alluminium casting of the inlet manifold cracked, separating from the casting and unusable, fortunately I had a spare.
I stripped the damaged rubber from the scrap casting and inserted 2 steel shouldered sleeves into the casting to extend this was my casting pattern, the finished all alli casting should be a direct replacement, its length is enough to fit 2 short lengths of rubber hose with 4 hose clips to retain everything together and hold the carb in place, anybody want to try one
John