Ah that's great mate....Thanks a lot!
It does seem a shame to strip the NOS one....
The funny thing is, on my original BITD DP (which I am building a replica of) I sanded the blue paint off the top
so it was just bare aluminium!
I'll have a think about the Black one....Took me ages to find...I don't think I've even seen another Blue one since mine in 1985!