Thoughts on conserving something like this?

[Revenant]

My mother has a friend from Bulgaria who had some coins given to her. They were from 1881 and had been found at an excavation (I think of some old castle). They were deemed unnecessary/undesirable so her friend at the mint gave them to her and she gave them to my mother for me. They're black as coal and environmentally damaged. I have been considering having them conserved.

 

Do any of you think that coins like this are worth conserving and how much do you think it would run me per coin (2 coins total)? Are there any special instructions that I would need to include? Would they definitely come back in NCS slabs or would I need to specify that (I want them back in a case)?

 

I can't understand them, just that one says "10" and one says "5." I don't have a picture of the "5" coin. They're both from 1881.

[physics-fan3.14]

You can conserve them if you want, but they are not worth it from a numismatic viewpoint. You have 5 and 10 Stotinki coins, and they are in Krause for $15 and $9 in XF, respectively.

[RI AL]

I was just wondering if "black as coal" necessarily meant environmentally damaged. When I think of zinc coins of Germany, Belgium, France, Austria from the ww2 years, they generally are black as coal once circulated, but not necessarily ED. Of course, that's what zinc does, but your 2 copper nickel coins, couldn't they just be deeply toned?? (Though I don't recall seeing many CN coins that dark.) Just wondering.

 

RI AL