Good morning,
If all you are missing is the BMDC board, it might be worth having someone come out and look at it. When I go out on service calls, I try and take spare parts with me if I have any for that machine. Recently we had a customer trade in an EZ Trak for an Acu-Rite MillPWR G2 retrofit, so I have an entire control console to help troubleshoot with. If you can find someone near you who has spare parts, they should be able to use their parts to at least troubleshoot your unit or tell you what all is wrong with it. We can still get new or remanufactured parts for the EZ Trak, so that isn't an issue.
Where are you located?
There are many different options out there as far as new retrofit kits. I guess it all depends on how much you want to spend and who you call. We are a distributor for Acu-Rite, so that is the retrofit kit we offer. But there are countless brands out there.
If you decide to only use the mill as a manual mill, msg me please.
Jon
H&W Machine Repair