i've never heard of them before. site is a bit cludgey, more like a manufacturer list than a webshop.
of course, they are still in the early 1970s as far as ordering (eg none of them are secure).
sure it's a big job, but there have been offers to help him for free on this and other model forums.
Southpier, There are people with photobuckets full of photos of Modelhaus product that you need to find.
check this one out for a good start
http://public.fotki.com/drasticplasticsmcc/1/2/1/after-market-source/modelhaus/