It seems both the Ampex and the Presto were based on the Magnetophon (which makes perfect sense).... below I is part of the story on Presto (taken from the Presto History page)... Engineers from Presto went on to a Scully to eventually redesigned their transports, it's an interesting history (here is a short excerpt). http://www.prestohistory.com/Presto.htm
"During the world war II years, Presto was heavily involved with government and military production. Through George Saliba's contacts with MIT, Presto was able to secure contracts for building such equipment as Location/Range finding equipment installed in NY harbor to detect submarines;test equipment for Radar installations/ Long Range Navigation for overseas lend/lease; as well as developing navigation simulation equipment for the Marines training for the Invasion of Japan (2). For these services, Presto was awarded the prestigious Army-Navy E award for it's help in the war effort.
After the war, Presto, who had relied heavily on their disc recording equipment, needed to expand for the future. Some one involved with the Nuemberg Trials at wars end, friends with the Principles at Presto, sent 2 German tape recorders used at the trials to Presto. They were military models, brand unknown, but must have been Magnetophone recorders. They were very ruggedly built, and were of the three motor design (2). That action resulted in Presto entering the tape recorder field.
Since Bing Crosby Enterprises had invested money in Ampex,developing the tape recorder at about the same time, Presto was in a catch up mode, and never reached the success of Ampex in acceptance. Many broadcast stations who had their disc equipment, purchased their tape recorders. Presto stayed with the 3 motor design, and never entered the home consumer market.
Arthur Gruber, son of Morris, worked for a time for Presto designing the tape transport systems of their later models. Shortly after the company was sold, he and several other engineers were employed by Scully and re-designed the Scully tape recorders, which were very advanced in their field at that time. Arthur was chief engineer and vice president of Scully Recording Corp from 1961 to 1968. Arthur died November 27,2001.
Presto also was help to CBS Labs in the development of the Long Play 33 1/3 microgroove record (2)."