Nice pictures. I like the low bars on it. I don't remember seeing many 400cc versions. I remember some 350cc (a friend of mine had a red one), lots of 500's and a few 750's. My nephew recently bought a 250cc triple and I don't ever remember seeing one of those.
I get Motorcycle Classics magazine and in the last issue, Jan./Feb. 2011, there is a nice article on the H1. I'm sure that once you get it on the road, it will draw a crowd where ever you go.
It should be a great drag bike. The article mentioned above, said that stock it would run about 12.8 in the 1/4 mile. With 60 hp and only 400 lbs, it is a rocket ship!! With a little porting, pipes and carb work, as well as stripping it down a bit might get it into the 11's if you can hang on!!
I hope to have my Bultaco on the road this year sometime. We'll see.