Possible Broken Cotter Pin?

[gramophoneshane]

It actually looks like a Thorens soundbox (or a copy), and I think (?) the diaphragm is mica, and you can see a pattern through the mica?
It almost appears you can see the bore at the back through the diaphragm, although the 4 shapes also appear to overhang the bore, so I'm not sure what's going on there.

[estott]

It appears to me that the diaphragm is a piece of molded plastic. The arm could be Thorens, or a copy: Heineman was an importer of phonograph parts before he started manufacturing.

[Goach2]

Even if this is an early 'imported' piece, should the Heineman parts still fit?

[Player-Tone]

I have the same motor, a ‘Heineman No. 77’, and was wondering how the table is removed. Does it pull straight off or unscrew from the spindle?

Mine is stuck and I don’t want to force it up if it has threads, nor do I want to try and twist it off if it has a square shaft.

Thanks.