I agree with HBC, that "permanent" marking is not the best practice, but sometimes a paper tag can be problematic as well (tearing, fading, visibility on displayed items). We number our vehicles in the same fashion as many other objects in our collection - by painting the number using appropriate reversible media (usually a layer of soluvar and white ink) in a consistent location (left rear taillight area for automobiles, on the metal mounting ring not the plastic light cover; lower left body for horse drawn vehicles). Now, assigning the number itself is another question - particularly vis a vis parts, an issue that we're actively discussing in procedures meetings here. Terry Beamsley (formerly Terry Grose of the Strecker Museum Complex, Baylor U.) Registrar Henry Ford Museum & Greenfield Village 313/271-1620 x 575 [log in to unmask] or [log in to unmask]