Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

What catalogs are you looking for? Many of the German ones are reprints published over 30 years ago and are now out-of-print. That said they can often be found on Ebay if you keep looking. The Schiffmann series is probably the best for German engines (2005 I think, but no accessories) and may still be available in Germany (?).