Steve Potts is next to Tom Ritchey probably the best (steel) frame builder in (my) MTB world. Other than Tom, Steve was part of the WTB and focused this brand and its innovative parts during the late 80s and 90s. 

Steve always build frames, primarily custom frames. His Siganture frames are the fully fillet brazed frames. Starting 1982 he continued these models. In 1986 and 1987 Steve started a project called SWIFT. The Swift aimed to serve the mid market, beeing only half fillet brazed and "only" equipped with a Suntour group, while the Signature constantly used WTB and customer parts. There where not many catalogues on the Signature, but below there is one describing more from it.

Next to his fantastic frames, I think his fork is another master piece he invented, the Type II fork. Charlie Cunningham, Ibis, Willits and others copied them.

Steve produced the fork in many variations, fillet brazed. tig welded, coping different hub dimensions (up to 118mm) or with rack and fender mounts. Even today one can buy the fork at his shop for 650b and 700c frames.

Here some material from the sales brochures and a collection of fork versions taken from a Germany MTB classic forum: https://www.mtb-news.de/forum/t/type-2-gabel-information.949109/.

His last strike for the steel frames was Cross Country Racer. Starting in the late 80s, this model aimed to be lighter and sportive. There is not many documentation on those, but my thesis is that based on this models attribute - half fillet brazed, Ritchey tubes, starting longer head tubes, Steve and his WTB crew build the WTB Phoenix.