This looks kinda intriguing:
https://www.ebay.com/itm/jelco-VTA-for-sa-370-750-ts-550-tonearms-turntable/153008593940?ssPageName=...
I have a couple of Jelco arms that this will work on. Wish it had it's own base for the micrometer to raise and lower off of, but if the arm base and/or the armboard is large enough it should work okay...
https://www.ebay.com/itm/jelco-VTA-for-sa-370-750-ts-550-tonearms-turntable/153008593940?ssPageName=...
I have a couple of Jelco arms that this will work on. Wish it had it's own base for the micrometer to raise and lower off of, but if the arm base and/or the armboard is large enough it should work okay...