Hollow Thrush Mufflers (vintage?)
Thush mufflers never freekin' had enough metal in them to last long enough to become "vintage." They were junk. Absolute junk. All you had to do, back then, and I did, was to take a Thrush in one hand and balance it on your hand, arm extended to get a feel of the WEIGHT.
Then take just about any other muffler in your opposite hand and ATTEMPT to do the same thing!!!