Encrusted Old Coins Now Have Details Showing Need To Identify Please Help

Coin#1
Side#2

That's a Constantinopolis commemorative - 'victory on prow', isn't it?

The coin I scratched
Coin#3
Side#1

The remainder that need time to soak.

It is possible that the hard material you are struggling to remove is patina. That should not be removed.

Olive oil is where you need to start, but not for a day or two per coin. Use it for WEEKS at a time per coin.

Do not use brass or other metal brushes for harsh cleaning.

More of the detail of a coin will be preserved if you use a very gentle, light touch with your cleaning, and do not hurry (anxious as you may be to see the design).

Thank you all for your input, and I did accelerate the process in theses last few days. I began by reading that you soak your coins in olive oil to loosen the crust from the coin. In everything I read and watched it was suppose to get much softer and flake/crumb off fairly easy. Never had that happen. First soak was 3 or 4 days. I used a toothbrush and soapy distilled water; with plain distilled rinse. There was almost no change in the density or thickness of crust. So I began allowing the coins to soak in bags for a week at a time. Then about a week ago I ran across an article and videos about adding heat to your olive oil coin bath. I used a small gas burner on low for 15 minute intervals, then 30, and the 45 minuter intervals. finally some of the crust gave way with the addition of a toothpick like demonstrated, and a size able amount of pressure. In demonstration it was described as just about no pressure to remove the crust. So I began to think that someone had spilled glue or paint etc. on the coin to from that hard of an exterior. I used the wrong muscle. I should have researched how to for example use a pool test kit to perhaps identify the material incasing the coin to find alternative methods of degrading the integrity of the coins crust. I now realized a second lesson was learned in that moment; when you are tired take your butt to bed. So I obviously pressed on using the wrong muscle and removed the crust down to the coin. While I read and watched a couple videos I was giving the coins another warm bath. Final thoughts were to get the coins more visible to post. Ah, look here third lesson the fool rushed. It may have been a less that perfect trip, but I thoroughly enjoyed the challenge and I am always ready to learn more through research. Alright Critique me further GO ;-)

I have only one thing to say about your coins...

R.I.P.

Thank you Spence, and I only paid twenty dollars for 400 wheat pennies, some amazing old bus tokens, 5 Indian head pennies, 6 Buffalo nickels, a ton of world coins half are silver, and those 9 encrusted coins. I am not going anywhere, and I look forward to the future. Sorry for the late reply, but I am in the middle of moving right now. I have a vast amount of rare coins and they all go to my sons coin collecting. I am blessed with a son who appreciates this hobby. He calls the good ones diamonds, and he is so lucky when we are roll hunting lol! Little stinker opened three rolls of halves the other day, and found one proof and 2 silver JFK. That son of mine is amazing :-)