Dave Murray´s number 1 is the black Strat, 1957 neck , 1963 body, that is 1 5/8". That guitar does not have a FR but in the 80s he used several vintage Strats that were retrofitted with FR, therefore they had R2s.
Adrian´s smith original Jacksons from Somewhere in Time were patterned after a 1955 Strat that he keeps in his house, supposedly for collection only, therefore they should be R2s.
Before being endorsed by Jackson again one of his favourite guitars in the early 2000s was a Fender Strat Classic USA Floyd Rose with R2.
P.S. I have a Kramer Pro-axe with a 40mm neck and a rare R1 nut...no issue whatsoever to play even with that narrow neck.
