I found a website called 1943MB.com the other day and thought that it had some useful information.  I didn’t realize it until now, but there’s a list of similar sites.  While they look similar, they appear to have at least some different information (I didn’t investigate too closely). For example, the 1941MB.com site has a link to a slat grille rebuild.

• http://www.1941mb.com
• http://www.1942MB.com
• http://www.1943MB.com
• http://www.1944MB.com
• http://www.1945MB.com
• http://www.1942GPW.com
• http://www.1943GPW.com
• http://www.1944GPW.com
• http://www.1945GPW.com

One cool feature is the Napa Online Website Link for parts.  Here’s a snapshot of it below.