Dave,
Here's a shot of one of the Big Cars in Stefano's display at VF this Spring. I swore these were vintage Inglewoods, but they were M/Ts. Nearly an exact reproduction of the old Inglewood Pos-A-Trac tread.
I still have my old M/T L-60 14s, (although they have virtually ZERO tread left) but they have the typical M/T tread design. My M/Ts have a full 10½" tread width while the ProTracs have just over 10".
(photo courtesy of Kwhizz)