I stand corrected and will hopefully know better next time :jimDon't confuse ROLA/Celestion B024/B025 with T651/T652, although they look quite similar.
Rola G12 alnico(with the large screws on top) and from the late '50s..........I'm interested in these as they may be 12 or 15 watt? What do you guys reckon.
12w, they'll blow in an AC15.
652's were 20w.
FWIW, Jim Elyea says in the Vox book that ca. mid '59 Celestion engineers set out to increase the power handling of the B024 specifically for evolving guitar amps, ended up switching from aluminum wire VC that had been used previously on B024 to copper, also reinforced the braided leads to the terminals, reinforced the cone with 1/2" of some then-unusual doping, for 15W rating of the T530 in summer 1960 (pp. 268-69). They had also experimented with some other things, including non-paper VC former additions.
Jeff