From my non-commercial blog...
It's a well-known fact that early-80's Tama Imperialstar "King-Beat" snares and some Superstar (Mastercraft) models have lugs that are prone to crack under extreme pressure.
Drum sites are full of guys lamenting a busted lug on their beloved old 80's Tama. Looking for replacement lugs? Well, you've just found 'em.
Photos and more info here...
(no ads, just pure drum-geek fun)
http://maturedrummer.blogspot.hu/2015/03/tama-imperialstar-king-beat-snare.html