Not necessarily a better case...pointed crown guard "PCG" cases are sought after, more likely the gilt dials may have been replaced at service. You see them (PCG cases) for sale with service dials occasionally. I prefer the standard CG's myself, but some really like the PCG's. There are many variables on vintage watches and especially vintage GMT's. The small versus large GMT hand and the correct date wheels. This stuff gets debated all the time. Most would say the small hand was used through 1966 and maybe a little later with the gilt dials and then the larger hand was used when the dials were changed to matte in late 1966. 66 was the big transition for Rolex moving from gilt to matte dials. So you see both versions in 66 for GMT, Sub, Explorers. Most would also agree that the original date wheels on the GMT had closed 6's and 9's, round 3's and a hooked 7's up until sometime in the early 70's. This is a decent source for quick information; although I do not agree with all of it. http://www.gmtmasterhistory.com/