It doesn't look to be in bad condition. I've always thought, "if you can tell what it is, don't clean it. If you can't tell what it is, clean it." I have some ancient roman coins that look like clumbs of gravel and dirt. I haven't gotten to cleaning them yet, but that's one case in which I feel it is okay to clean
https://www.cointalk.com/threads/does-anyone-know-what-this-is-pretty-cool-whatever-it-is.301393/ In case anyone else wants to see mine. Mine was deemed most likely a fake. (On one side at least)
Can acid take off the plating and not cause wear on the strike? I've seen coins like this, and I just assumed the plating came off by one way or another.
I find it near impossible for an acid to dissolve copper, but not zinc, which is only but more reactive.