In contrast to Sonor's and Premier's 'undersize' shells, RB Gretsch snare drums are notorious for, in some cases, accepting modern heads with difficulty or, with regard to certain brand's models, not at all. It's not consistent. With respect to my two 6 ply RB snares, the older, c.'59-60, is
very tight (Remos literally 'squeek' on). The other, c.'63-64, presents no such problem.
A Gretsch RB snare's bearing edge bevels
straight away from the outer edge. Perhaps this is why many have claimed RB Gretsch snare drums 'difficult' or 'impossible' to tune satisfactorily. (Personally, I think that the tuning 'problem' lies with the deep snare beds. You've got to really crank the reso.)
Btw, Rogers snares from the mid 60s had quite similar bearing edges... re-rings notwithstanding... which I believe to be a vital component in their 'crisp', 'modern' response.
On the other hand, the bearing edges of RB Gretsch toms and kicks were
rounded over from the outer edge to the crown. I believe in the case of their top line, they still are. This is why custom seating of calf heads on RB sets may be critical for achieving the best response.
More than one way to skin a drum.
Ron