This is an early version with the original patent number on the end of the hoop clamp and no Ludwig logo. Both felts are there and in excellent condition, with one of the plates being slightly bent.
Vintage 1920s-1930s Leedy & Ludwig No. 324 Hoop Mount Bass Drum Spurs
LUDWIG 60s Vintage Hoop Clamp BASS DRUM MUFFLER Mute Tone Control Part Chrome
Wm F LUDWIG WFL 40s 50s Vtg Bass Drum MUFFLER Hoop Clamp Tone Control Part Swing
WALBERG & AUGE Hoop Clamp BASS DRUM MUFFLER External Part Tone Control 40s Vtg
Pearl Star Bass Drum MUFFLER External Hoop Clamp Mute Tone Control Part MIJ 60s