Information on Schramm Pneumatractors is very limited. I invite anyone with more details to email me.
Schramm built tractors based on International Harvester frames and engines for a period between the 1950s and 1970s. These tractors were, essentially, portable air compressor units and not designed for tillage or other typical tractor work. Although some may have been fitted with backhoes to complement the jack hammer or other air tools. Schramm no longer builds tractors or air compressors.
Schramm - official site
Schramm history - an article detailing the history of Schramm