Hi Will Fly,

I am 99.99% certain that Gibson never used cedar for its tops in the 60s/70s/(?80s) or before - all spruce - so this would apply to both the Epiphone (Gibson) Texan and J45 you mention. So if there is an issue, it is certainly not due to the species of the timber used. And no, the tops should not "play out" - in general, 50s ones are considered better (now and possibly then as well) than 60s, 40s than 50s, and 30s than 40s. (20s are different because often they were not braced for steel). The most desirable and expensive vintage steel string guitars today come from the 30s (both Martin and Gibson) and there is no suggestion that the tops are "too old" or "played out"... e.g. take a look at

https://cartervintage.com/collections/acoustic-guitars?sort_by=price-descending

Just sayin'!

Cheers - Tony