Very interested to see this post as within the last month I have been through a saga with these Myford fine feed gears.
I bought one from Myford via Ebay for my ML7R , when it turned up the bore was tapered and would only fit on the shaft for about a third of its length, trying with a piece of silver steel confirmed that the bore was tapered rather than any fault with the shaft, after a few exchanges of messages I returned it. After a number of days of hearing nothing I had to send an inquiry as to what was going on as far as a replacement was concerned, followed by a phone call.
The impression I was given on the phone was that this was a rare occurrence and was I sure the fault was not with my machine. A new gear was sent which fitted the shaft, but ran out so badly that it would only revolve half a turn, to use it would I feel have stripped the fibre gears. At this I gave up and returned it via the Ebay returns scheme, and received a paypal refund. I bought a secondhand gear off ebay which was cheaper and fitted perfectly. Very disappointed that such poor quality items are being sold under the Myford name, I suppose I could have fettled the second gear sent, but at just less than £40, why should I have to?
At the same time I bought two changewheels for my Colchester Bantam from RDG, these needed a bit of fettling to remove burrs, but they did fit ok and run true and mesh well. They were very cheap, much less than used ones go for, so I didn't mind doing a little work on them.
As ever you get what you pay for, but if you pay genuine article prices, I believe some quality control should be carried out before sending out.
Dave W