for any transformers already available through hairball or CAPI, please contact them.
for new design requests, if it is something not already available elsewhere, i’d like to help… but it isn’t usually feasible unless there is a need for 100pcs or more. if collectively the forum shows that level of interest for a new design, i’ll definitely take a look and see if i can work something out.
unfortunately the winder that had been making the EA-5002 for us closed their factory (after 65 years!). bringing up a new winder to make the part has been difficult (especially with COVID) so the supply has been constrained. check Hairball for availability.
CineMag makes their version of the 5002, but they also have long lead times.
The question is, do you want just 600:600, or all the available taps of an A-20? There are hundreds or thousands of good to great 600:600 models of all vintages out there. Personally I don't think we need another new one. But then, I have boxes full already...