Unusual Meltrope sound-box design ???

[Oedipus]

There is Meltrope IV, or rather, 4 -- photos attached, and I think I posted them here a few years back. It's a rarely seen bargain basement version, with no Wright back, and with two pips in the front mask instead of the two upper ball bearings. But there is also a version labelled III on the front and 'No 3' on the back which has two pips instead of the upper two balls, and also a more rounded rim to the body than normal. And, blow me down, if that 'Golden Melody' isn't one of them!