Johnny-B Eish, if google can't dig up the schematics/layout, then I'm not sure.
I've used this guy (Thereon Electronics works) and he's quite into the details, so even if he hasn't seen it before, he's got a decent chance of figuring it out - downside, he's in in Cpt
https://www.facebook.com/theronelectronicworks
I know the gear junkies have some old bits they use for spares - but that's the longest of shots - worth a email if you really want to exhaust all avenues!