There is a Youtube video by David Schramm that gives some pointers to doing the V joint. I think he uses the Fussen joint, what some people refer to as the Hauser V. In reality that joint dates long before Hauser. There are a number of variations. I'm guessing that the J.French one was the through V - the type that Romanillos employed.
Making accurate templates helps enormously, as does seriously sharp chisels. The best advice though is to get some scrap wood and do a couple of trials, just to get the feel.
