I wouldn't be one to spend that much on pro conservation, for something I was going to put in an album. But it did make me wonder, can you send a coin just to NCS? Skipping NGC and the cost of the grading?
I'd prob do what you did with the acetone while waiting for the next batch of the verdicare. One comment though, not really a suggestion. I always hesitate to use acetone on copper. Not that it damages it. But to me, the copper always looks duller after being in acetone. I don't find that with silver, gold or even clad coins.