raph, are you familiar with the research of Lucas de Groot? It's mainly concerned with parameters such as weight and width, less optical scaling, but he's very knowledgeable about interpolation maths in typography. (And of course, the IKARUS program did a lot of the groundbreaking in this area too.)

A friend of mine here in Australia, Nick Summers, owned a hot metal type foundry and bought one of MFB's pantographs when ATF's equipment was dispersed. He and I also met an ex-ATF employee around 1992/3 who was working on next-generation typographic layout software (this is around the time ATF released PostScript format fonts in optical scaled series - late 1980s). His name escapes me for the moment. I think I still have a copy of the program somewhere.

(update) The ATF guy's name is Henry Schneiker, and here's a contemporary article he wrote, Type Technologies Illuminated. The program mentioned is ATF Type Designer I (v1.4 & 1.5b, 1991). Jens Alfke was also on the project. Jens has one of the most enviable resumes in the industry.

I found IKARUS M (Mac versions 2.5 and 3.0, 1992), too.