When last I was heard from, the old copper tape I used for restoring this old track was old enough for the adhesive to fail, and the paint I used was terrible for traction. That, in addition to a moisture problem that swelled the slot too tight, made the restoration a disaster.
But, what ho! I have figured out a solution. The slot has been restored by wrapping a #120 grit sand paper piece around a plastic putty spreader rubbed vigorously around the track in the slots in all four lanes. The spot in the middle of the track that had a bump is flattened out (it was between a chicane and a hairpin and very tough to get right). So, I am about to putty in the transition between modules of track and paint.
There's a lot more coming, and from here on there will be pictures.