Hi Roger,

Good finds! I especially like the original envelope. From what I've found, Charles C. Merzbach was the main distributor for Marklin to service the entire USA. He took over following WWII and was the successor to Richard Marklin who was running the American import business for Marklin for about two decades. My guess is that Merzbach started in 1948 as many of the 1947 catalogs have a 1948 USA pricelist and order form with his name on it. I'm updating an article I wrote about American dealers and importers here:

http://marklinstop.com/2...n-importers-usa-part-ii/

Here's an example of that 1947/48 catalog:






Also, your catalog with the cover missing is Nr. 763 "Schienen-Anlagen Spur 00" that looks like this:



Although both catalogs might have print codes from the late 1930s they were used all the way up until the late 1940s (maybe even 50s). I'm curious, does the postage stamp on the envelope say '53?

Best wishes,

Paul