I think brake drums may be made of cast iron and are therefore bound to accumulate a degree of surface rust rather quickly...? My old +8 had the exterior of it`s brake drums painted with black two pack paint, some 20 years on they still look to be reasonably smart... Though how much paint coatings might reduce the efficiency of heat dissipation, I know not.
As for finding one loose screw... My expectations of general maintenance on a Morgan is to carry out a nut bolt and screw check on a regular basis as such is the limit on suspension travel/design that everything can receive a good shake up, and more so if you suffer rough road surfaces..?
