Came across this and ordered one for my JX-3P immediately..
http://organix.inque.org/jx3pexpansionkit/
Not a direct PG200 replacement, but something that’ll make the good ol’ 3P understand Midibox.. 
Slightly off-topic: I have an MKS-7 - no external hardware editor was ever made. Luckily it’s all editable with sysex, but it loses all user patches on power-down. I dream of a MIDIbox patch editor/librarian for it, with random patch generation…
Hey did you win that on eBay recently? 
Man that controller is absolutely do-able. You could make a function to send the patches when it powers on too
No, bought it about four or five years ago from a music shop in Brisbane over the web. $200. Unfortunately the idiot sent it to me in one layer of cardboard made out of two boxes sticky-taped together, and no padding of any kind. When it got here, two of the DCOs were funky. I shelved it and never got back to it. They could just be loose in their sockets, or they could need replacing. $$$
“Doctor Doctor..”
Lemme take that limited piece of **** out of your hands.. ;D
or then again: Midibox64 modified to good edit layout in with custom meta events and in patch mode and Your MKS-7 RoXX! (MKS-7 has a single edit buffer for the sounds, this would dump patch as SysEx when changing “patch” on midibox.. I’m been wondering about hacking into this machine.. (if I had one) and do some HW/SW modifications.)
Moebius
/edit p.s. Just hope the problem is in the oscillators not on the filters - the oscillators are standard digital counter chips.
This guy sells a fix, at 25 Euro per osc :-\
No, bought it about four or five years ago from a music shop in Brisbane over the web. $200. Unfortunately the idiot sent it to me in one layer of cardboard made out of two boxes sticky-taped together, and no padding of any kind. When it got here, two of the DCOs were funky. I shelved it and never got back to it. They could just be loose in their sockets, or they could need replacing. $$$
Bugger 
Well at least I don’t have to feel bad for pushing your bids up