Sonora No. 5 reproducer

[BillH_NJ]

Does anyone have knowledge about possible changes in the Sonora No. 5 reproducer? I have two Tonalic machines, a Concert and the Philharmonic that was recently discussed on this forum. I have four No. 5 reproducers and it appears that the one on the Philharmonic is different from the other three. The inner diameter on the Philharmonic appears to be ¾” while the other three reproducers are 11/16” and will not fit on the Philharmonic tonearm (although those three do fit the Concert). The back of the Philharmonic reproducer is marked B under the No. 5 designation. Two of the four have a locking screw while the other two just rely on a friction fit to hold the reproducer in place. Was there more than one type of No. 5?

Thanks,
Bill