Those are excellent tapes -- TDK EHG, JVC EX, SKC S-VHS.
But that's not a good VCR -- especially not for S-VHS and VHS-C source! Ideally, you'd want a Panasonic AG-1980P for the VHS-C tapes. Most normal VCRs, even good VCRs like JVC S-VHS decks, eat the tapes. Repear, EAT THE TAPES! That's not good.
Having so few tapes as you do, about 50 total, it would cost the same (or less) to just send the videos to a good service, rather than try to DIY and hope for the best. It's easier for you, and a service should have experience and skill at transferring video. (Keyword: should, so be careful who you select!)
We have services here at The Digital FAQ, but I'm not trying to hard sell you anything. Just telling you the facts of the situation. (If interesting,
Contact Us.)