See the recent MG post re: painting. It gives a step by step process of a good quality paint job. For painting, assuming you are not doing a frame off restoration, the fenders should be loosened and the beading removed. The car should then be striped, primed, sanded and painted. Then new beading replaced between panels as well as an anti corrosion joint strip (available through Moss, Victoria Brit, etc.) and the panels bolted, screwed back together.