My drums I ordered in 1987 have the double badges. I recall that sets I looked at prior to ordering my set also had them. Based on that recollection I'd say that they were doing that by 1985/86 but it could have been earlier.

My floor toms have just one badge and I don't recall seeing any Gretsch drum with legs having two badges but that doesn't mean it never happened..

Thanks. I have one post-Jasper era set of USA Rosewoods. All the rack toms are double badged, yet the 16x16 FT is not. This seems to support your 3 legs = 1 badge theory.