Removing and replacing any part of a control system is a
serious item here in Canada, and I suspect the FAA would take it pretty
serious, too. Here we have to have TWO people inspect any engine or
flight control system that's been "disturbed," and the signatures in
the logs to prove it. At least one has to be a licenced mechanic, and
the other has to be trained in what to look for. There have been
accidents in recent years when control systems were left loose or
connected backward (easy to do in many aircraft) and things came
unglued in a hurry, killing people. One of those was a 172 that had had
the control wheel shaft out, and the assembly looked good but was wrong
and it came apart in flight. The 150 has the same setup.
Aircraft upholstery shops are often certified to reweb belts.
Much cheaper than buying new. Check with some major structural repair
shops at a larger airport; they'll know who does them. Cessna now
demands that belts be replaced or rewebbed every ten years. I suppose
there perhaps have been a few failures in accidents.
Sometimes duct tape goop can be taken off acrylics with
isopropyl alcohol. I've also used acetone but you have to be mighty
quick about it or it'll start attacking the plexiglass. Never let
laquer thinner or MEK anywhere near it.

Dan
Dan