I'm not vaguely taking any responsibility for what may lead you astray, but I've recently spent an age looking for the din plug for the control socket of my Revox, involving googling and poring over endless DIN specs. all of which are like knitting fog.
This "female plug" (A contradiction in terms, I feel) rings a slight bell: on a quick google, I came up with a J4D, but I'm not sure whether that's a din or a mini-din.
However, when I googled that, I came up with these people, why not email them your photo and see if they can help?