Recently i acquired the Sanyo M9990k and wanted to make some mounts for the microphones the hm940 and 941's that are able to be fitted to the unit.Very hard to find these mics, what i love about the 940 mics is firstly the look of them, and it has the switch to operate the tape deck automatically.Anyhow i may have to see if i can find something similar but i went looking for some repro mounts and found some on Shapeways but they wanted like $75 dollars which is ridiculous so i decided to work on my designing them myself from pictures i could find of them and will be testing these out when i get a chance.I will post these up on my thingiverse page in a later post for everyone that would like to make them once i have thoroughly tested them with some mics attached, also if you need a set and don't own a printer just message me on my FB page.You can check out the progress here you may need to scroll down a bit to find it.
I search out mics once in a while, they're a lot easier to find then the mounts. I have one mic/mount for an old 70's AIWA and thought I could resin-cast it and duplicate it. It wouldn't be hard to also buy some aluminum angle and make your own, if you have access to a belt sander you could finish it it nicely. Mine mounts on the back with a thumbscrew, more are similar to yours with seat-belt type sockets on the side. Good luck!