I hope this helps...
The connector from the deck/motor assembly of my SP-10MkII into the SH-10E power supply is a Switchcraft A4M, which does look like a DIN 270 Degree 4 pin connector. I assume the power supply side is a mating D4F, but I am still digging in the garage for mine to be sure.
Switchcraft differed from DIN, if I remember, by having a locking tab that was depressed (it's on the power supply side) to release the connector. They are commonly used for microphone connections (in the 3 pin version the A3M and D3F.)
If you would like I can send in a photo of the cable end off the deck. I have no idea of the pinouts, but I think the Matsushita service manual lists them. I do remember they are quite 'hot', like +12, +30 Volts, and ground.
On edit: I found the SH-10E Power Supply, and the connector is a mating Switchcraft D4F. I can send pix, and if I find the service manual, I'll even look up the pinouts.
If you google Switchcraft A4M you'll find many distributors of Switchcraft and compatible products (e.g. Unicorn and others.) Unicorn calls theirs the XLR connector and that's another term I remember. HH