Substitute EIAJ tape stock?

[WildcatMatt]

I have a handful of 1/2" open reel machines ranging from the Sony CV-2600 through the AV-8650 and a Panasonic NV-3130 just for variety.

I also have several old tapes which date as far back as 1972, almost all of which exhibit sticky-shed syndrome and require baking for playback. None of the tapes are what I would consider "throwaway" in value and I'd really rather not have to bake one every time I want to do even rudimentary tests on one of the units.

Are there any other 1/2" formats I can "borrow" tape stock from, ideally that I could record to and play back from?

The obvious choice would be VHS since I have a bunch of it around and it's less than half the age of the EIAJ stock, but it seems thinner. I'm wondering about Betamax or even baseline Betacam tape.

Anyone have any experience in this realm?