Ok, I think I've got it now. So he's got two sets in blue strata (awesome looking wrap!) The first one, in the older threads, is the no-name Hoshino made set with the shark tooth lugs. This set shouldn't have re-rings in any of the drums, including the snare (please let me know if that is incorrect.)
The Riviera set, I still believe, is a Pearl made set from (I'm guessing) the mid to late 60s with re-rings in all the drums. I'm starting to think that Pearl wasn't using the Slingerland copy lugs in the 70s, or at least by the mid 70s. I think by then they were using the battleships, gold bars, and disco balls on mostly everything until they started using the standard 'diamond' lugs that we see on all the later MIJ and MIT stuff. Another reason I think the Riviera set is from the mid-late 60s is that it has the 'fat' Slingerland copy lugs. Pearl had two different types of Sling copies, the 'thin' ones and the 'fat' ones. I think that the thin ones were used earlier (and we seem to see less of these) and the fat ones are the ones we see more often on both Pearl labeled drums and on stencils (like my BDP Tempros.)
I dont know why Pearl put together a set with the clam shell lugs on the snare and Sling copy lugs on the bass and toms, but apparently they did. I could posit that the snare came from a center lug Riviera set, but that name just isn't as common as Stewart or Apollo, so I dont think that was the case - it's just a funky factory mismatched kit, which, as Osaka-bop pointed out on a different thread, Pearl had been known to put out from time to time.
In terms of the shell ply configuration, I'm not sure about the Riviera snare, but I can tell you about the two early Pearl snare I have. My WMP Jazzmaster snare (that has the same clam shell lugs) looks like it is actually 4 ply. My Pearl made red sparkle Norma snare is a very thin 3 ply shell. Unfortunately, I cant comment on the sound of these two snares as neither of them are in playing condition at the moment. The Jazzmaster needs the re-ring re-attached and has no strainer. The Norma shell has collapsed at the strainer spot. However, once I (eventually) get them up and running, I expect them to sound pretty much like the other MIJ wood snares, warm and 'smokey,' like Jonni describes, only tuned a bit lower considering how thin they are. Hopefully they wont be too difficult to tune up, but I'm not anticipating that given that they are 8 lug snares.