Well, well, well, a piccy of the very car! It definitely had a V8 in it, with 4 branches either side and very wide gearbox tunnel and wide arches, so it may well be one of the original G10s, or converted from the later G11 (MGB) to G10 (Ford V8) spec. As far as I can make out here
http://www.cottageclassics.co.uk/ginetta/ginettag10/ginettag10.htm, there seem to have been only 4 G10s made originally, as it refers to Chassis number 4 and "the three other cars", but it seems that it is possible to convert from the G11 specification
http://www.cottageclassics.co.uk/ginetta/ginettag10/g10ssold/g10ssold.htm. Either way, it was nice to look at in Gulf colours, and it's not exactly a car in plentiful supply!
MG Mark