Reddit reviews Guardhouse 2.5 x 2.5 Double-Pocket Unplasticized Coin Flips Pack of 100 with Inserts

for raw coins? I like flips

The ones that cause the issues are the "soft" ones. If you have rigid flips that feel like they would crack if you bent it (they don't actually crack, just fold and leave a crease), then you should be okay. The soft ones are made soft with PVC which does do damage to coins

EDIT: I think provident sends out non-PVC flips. I ordered from them once or twice, and have since received coins from others in provident flips, and they all feel safe. If you want to buy a bunch more to keep on hand, just in case, you can find them on amazon

> I'd greatly appreciate your help in getting a clue as to what I have,

So hopefully the comments so far are helping identify them. If not, maybe sort them into what you know and what you don't, and post pics of a few at a time for identification help. Seeing several dozen coins is a bit overwhelming.

> and, what I should do to keep them nice.

Until you get a better idea of what it is you have and possible value, I would keep them all holdered, either in the existing holders or buying some inexpensive mylar coin flips (the clear plastic envelopes in your 1st and 2nd pics, and others). Example.

Older coin flips contained PVC, which can be harmful to coins. If the existing flips seem very soft and pliable, they may contain PVC, so consider rehoming those coins in new PVC-free mylar flips.

Coins in the hard holders, or the stapled cardboard holders, are probably fine for now.

Handle the coins only by their edges, and try not to touch the surfaces. The usual recommendation is to wear cotton gloves to prevent oils from your fingers getting on the coins, but disposable nitrile gloves do the same trick and are easier to use. As long as you get the powder-free ones, they won't harm coins.

Best not to attempt to clean or wash any of the coins. Cleaning techniques tend to abrade the coin surface and/or impart an unnatural sheen. Even if the harmful effects are not immediately evident to you, they are to collectors, and can destroy or at least significantly reduce the collector appeal (and thus the value) of the coin.

Nice collection! Good luck with it.