I know, I was being facetious to prove a point! I also know the Britains TW-20 was never marketed as 1:34, it was a measuring error, which is why they changed it to a 7710, because it was too small to be a TW!
I'm sorry, but you're very wrong, the 6700 and 7700 were shortened 8700/9700s, the design of which has no correlation with 8/900 or 8/9600. The 6700 and 7700 may have had the same engine as the 6600 and 7600 respectively, but the design was different.
To go to the original point, the 7810 bonnet was simply an extended 7610 one, the TW-15 one is the same as the 8700/9700.