Well, this is supposed to be a replica of a well-known sports/racing car of the 1950s, hand-built by someone, but I'm pretty sure he'll have used a proprietary body rather than laid his own design in glass-fibre. I'm afraid it doesn't mention which proprietary body was used though, so I'm afraid I can't answer your question!
I do agree the front looks very much like that H.G. (I posted the ad in the thread yesterday) but even If it is one that's not the answer I'm looking for (since I didn't know that fact!) so it wouldn't really get anyone anywhere with the answer..
Sorry.