The skier holding the trophy in post#7 sure looks like Chris Thorne, one of the top bumpers of that era. After the Midas/PFA tours folded in about '74-75, he started the Western Pro Freestyle Tour with his wife Kathy. It was just bumps and ballet (later purely bumps), as no areas would insure for an aerial contest and ballet began to fall out of favor.
The Salomon 444 heel and the 555 toe was a very common 'demo' binding of that era as well. The 444 heel had a version with an extended track was one of the first 'performance bindings' to allow significant range of adjustment for boot size. I actually had this setup on a pair of PRE 1200's which a rep had given me in '77 or '78.
In the OLIN line, another version of the Mark IV was built as a bump ski. The Mark IV COMP (orange and white) had a squared tip and a more radically turned up tail than most skis, similar to the Hart Freestyle and the Kastle Freestyle Pro.
Olin also built a Mark VII (two tone gray), the last of the "MARK" series. This model was one of the first skis to begin experimenting with exotic fibers, in this case it used ARAMID (sp?) fiber, which was used in building car tires at the time.
The Mark VII was not the last of the Mark series, there was a Mark XXV for the 25th anniversary of the Mark series. I think it was 25th, could have been XX.