The 16500C board rot problem.

So this is my first post here but perhaps somebody can help me. Awhile ago I purchased a 16500C from Japan. It posts fine. Disk in it seems fine. But unfortunately as I have learned all of these machines will share a common problem which is that the 16557D cards ( and similar ) have the plastic rails on the bottom of them and whatever combination of glue chemistry and time has resulted in the tracks under those plastic rails rotting out. Now I carefully removed the plastic rails and got myself a decent microscope and managed to repair a track on one board which did enable it to get further in the diagnostic tests than it had previously. I felt pretty smart at this point! But alas I could get it to go no further. I think the rot is deeper. I have left the other board alone aside from removing the plastic tracks to stop the rot going further. Next I asked in the HP group about finding replacement boards. The problem is lots of these boards are around pulled but none of them can be verified as tested working and I expect all of them to have the same issues. This is a real pity as the 16500C seems a very nice machine. Just as it is a boat anchor in its current state.