What an awesome thread! Never knew there were so many designs of linkage forks. One omission though: The Lawwill Leader! First read about them in 1992, never saw one with my own eyes. I think they were later manufactured by Control Tech, no idea on the earlier models.
The OP did mention them in passing, so I didn't put them on my list.
A familiar setup...here's mine on the RS-1
:
The original Lawwill Leaders had a welded or brazed steel fork legs, with the standard shock mounted onto a pivot on the underside of the handlebar stem and a swingarm linkage at the crown to control fore/aft movement.
The paired, but out-of-parallel and different length linkages give a vertical axle path, so almost no change in trail throughout travel.1990/91
This changed to the machined crown, linkages and aluminium legs of the Leader2 when Control Tech got on board. Proprietary shock rigidly mounted to the crown, with a pivot/eye at the bottom of the shock:1992
Then there is the Leader3, which is pretty similar except for the side plate trunnion mounting for the shock, so now has a rigid unicrown front fork, with a pivot on the shock body to allow it to rock fore/aft slightly during travel. More rigid and avoids the side loadings on the shock shaft:
Mert Lawwill ran a few different brands of disc brake on his prototypes, including Shimano and MountainCycles ProStop.
The one on the blue RS-1/Leader2 is the later Hope mechanical that Fisher adopted for their bike, rather than the p**s poor ProStop that was used at the start of production.
Here are a few in Mert's own workshop:
All the best,