Surfer,
Sachs didn't make a 48mm bore that I know of. They made the 122super/SL,123 (47x40mm) and 120 super/SI (49x36mm). Husky made the 61 Rancher, 61(48x34mm), A65 and L65(48x36mm) between 1968 and 1974. The case was orange as is the original color of your saw. I think that your engine is a Husky between 61cc and 65cc depending on the stroke lenght.

Dave