Allan:
There are a couple of Meffert Drilling threads on the NE BBS and here is one: http://forums.nitroexpress.com/showflat.php?Cat=&Number=153366&page=&fpart=&vc=1 . It could very easly be that Imm. Meffert subed the some of the work to the craftsmen in Zella-Mehlis but if proofed there I would expect to see a date code. I'd say that there were very few firms that didn't source some work, whether lower rung or high end craftsmanship work.

Kind Regards,

Raimey
rse