Looks like the same Potter Tape Drives that were used on the UNIVAC 1240 Magnetic Tape Unit. The UNIVAC generation of equipment before the 1540's at VCFed. The T-handle was to retract the tension arms mechanically rather than with a motor as the later units had. Duane On 7/14/2017 2:43 PM, Christian Liendo via vcf-midatlantic wrote:

I get someone in the Pittsburgh area might want to know about this.

https://arstechnica.com/science/2017/07/nasa-computer-engineer-basement/