Chain Case Part numbers question

[qwispichkn]

I'm looking to replace my upper and lower chain cases for a 65 Dream CA77. Parts manuals list 2 different numbers, for 10001-1014673 and 1014674 and newer.

Mine falls in the later and I can't find a replacement for the lower case. But both upper and lower cases are still available for early models. Question is, will the earlier cases fit my later model?

Thanks for any help