I know I will catch flack but so what.
If I had the chip I would keep it exactly as it currently is.
So you removed some paint. Any difference than removing some grime and dirt.
It remains obvious that at some point in time green paint had been applied to the chip. It is not as if it was professional cleaned of ALL green paint and represented as 'The only known unpainted example of this chip'.
You have documented its existance and I believe there should be some club location where this type of information is stored and made available to any and all club members. In fact it should be available to anyone doing their homework.
I, personally, would not destroy or encase or do anything that would harm the item.
OK folks, tell me I am wrong but please do it by email rather than start a flame on the BB. Others could care less what you think of me, I hope.
Wishing all enough,
Dick Staeffler R-3828