I believe these were made by Pearl. and the shells will date them (you probably already know):Thin with rerings through 1967ish. Thick with no rings 1968ish and later.This rule is general and applies to both Pearl and Star made kits. Congrats - that is a great score! If you are like me - you will build an entire set of flat based MIJ hardware to go with your vintage MIJs. Scores like this is a great help toward that goal. Not quite as rugged, not quite as reliable, etc. - but they still work just fine if you make sure they are complete and in good condition. Tune the heads to the shells - and these will sound great. SOme are even shocked at how good they can sound. If you have any tuning issues - just have the edges recut - and it can totally liberate them.
Thanks for the info...didn't know that about the re-ring dating. I have a couple other MIJ kits and they are both no re-ring. I should get this kit from my brother on saturday....I'm curious to see it!