Repairing a Bondo repair

My 71 Scamp has had some rust damage repaired with Bondo in several locations on the car. I’m not really worried about most of them, but the C pillar repair is beginning to crack and bubble just a bit. View attachment 1715500358 View attachment 1715500359 View attachment 1715500360 View attachment 1715500361

I have a vinyl top I plan to have installed, and I don’t want to trap this underneath. I have zero bodywork experience, is this something that’s approachable by someone with no Bondo experience?
Most likely there is rust underneath the bondo. That will probably require a patch of some sort and a lot of paint work. Under no circumstance
install a vinyl top over that, that would only make it worse. It may have the same issues on the other side as well.