[Arran]

 You probably won't find any Grundigs from the 1940s, they were most definately a post war company and didn't get into the export business until they teamed up with Majestic in the mid 1950s, so most of their products are from about that time up until the early 1970s. I try to stay away from German sets as a rule, one Achilles heel most have is the piano key bandswitch assembly, whoever thought up the idea to use the bandswitch mechanism to turn the set on and off should have been shot as it eventually wears out the contacts. Of course they are also a dirt trap so they have all sorts of problems with dust and crud getting into them.
The Grundigs from the 1960s at least also had a habit of using polystyrene in the slides when they should have used phenolic, which can be destroyed by the wrong solvents getting in there. If they had built these assemblies like Philco did in their 1942 to 1949 sets they would never have these problems, thicker contacts, and slides made out of phenolic, they did it right the first time. I have a Telefunken with a failed power switch and, if I feel motivated enough, I will retrofit the set with a normal on-off tone/volume type switch that properly designed radios have.
Regards
Arran