Front camber is not a problem as this is adjustable, assuming nothing is bent....worth checking wishbone.
Surface rust is not a huge problem, but sometimes difficult to eradicate completely without cutting out all the rust area and welding in new steel. Most cars this age will have some problem with this....sometimes 'repaired', only to appear later.
Serious rust is underneath....look for corrosion round the area where the rear beam bolts onto the floor section, get underneath with a torch and have a good poke with a screwdriver....this is common in Mk1s and expensive to repair properly unless you are handy with welding kit, then it's time consuming. But finding a bit of evidence here is a good bargaining point.
