How did I "fix" it?

Like this. That's a PGM-II, a modified mc18 loom, mc18 temperature sender, mc21 flywheel and mc18 clocks. Quite a drastic solution eh? And it's just a racebike so no need to worry about things like ignition lock, steering lock, petrol cap lock etc.
Worked fine, made exacty the same power, started a bit easier.
I then got hold of another PGM-IV from Japan when I sold the bike as I figured an mc28/mc18 hybrid was worth a lot less.

A PGM-III (from an mc21) would be an easier swap as the reg/rec plug, TPS, stator plug and carb solenniod plugs are the same as the mc28. The mc18 plugs are all different.

I see you've asked Moriwaki-man too, that is as far as I know the only other option.

If it can't be fixed then the cards you have are only of use for getting Moriwaki-man to get them re-programmed to match another PGM-IV and that's going to be a very expensive way round the problem. It'd be cheaper to source a PGM-IV from Japan with all the cards you want though you may have to wait a while for one to turn up.

So your options are;
1) maybe fix it if it can be done.
2) fit wiring and other bits from earlier model. There are a lot of little things to sort out here if it's a roadbike.
3) buy another PGM-IV from somewhere.

Sorry for giving you nothing but bad news!
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