I have a gretsch G6193 In mint condition 1993 model still has the guarantee un filled in in the original case ! i got it from a collector who just had it locked away.
I have become unwell and am thinking of selling my guitars.
Some guy just offered me £700 for it any ideas or help would be very welcome
In perfect "new" condition the price here in the States would be almost $2500.00.

If its as good as you say, I wouldn't take less than £1350 at today's exchange rate. He gets a little break in the price of new and you almost get the "new" condition price.

If he doesn't like it, then sell it elsewhere. You could probably get a better price at a pawn shop, or you could Ebay that mother.