Hi Mike,
Thanks for your post.
A side effect of transitioning SD7.3 to 64-bit is that older USB dongles – which have only 32-bit drivers – cannot be recognized. I believe your dongles were first issued in 2002, so they would certainly fall into the category of older dongles!
The immediate and best fix would be to switch your dongle-based licenses to be Cloud-based. This has all the advantages of hardware-based licensing but none of the disadvantages.
Shall we go ahead and switch your licenses over to be Cloud-based?