Random orbital sander and 320 grit??
No kidding, not for the faint of heart!!!!!
Dang, sounds like luthier work by Tim Taylor, featuring MORE POWER!!!
I suspect there are many similarities between hollowbodies from that era. I am pretty sure that Univox, Aria, Lyle and Epiphone all would have the same or nearly the same dimensions, since they were all built in the same factory. Since most were copying Gibson, it would make sense that they would head the same direction. However, that wouldn't make parts interchangeable.
I'll try to get a better photo of that Lyle - I'm sure you would enjoy seeing it.
And to ask a detail technique question, when you mention using a razor blade scraper, do you point the blade toward the direction of travel, or drag the blade behind your hand (tip facing back) as you scrape?
I figure it doesn't hurt to ask the guy who has BTDT with such great results.