GNT 3601 tape punch docs?

Probably a stretch but wondering if anyone has any info (manual, pinouts, service documentation) for a GNT model 3601 8-bit (1") paper tape punch. It was probably better known in the CNC / automated machining world than in computing but my hope is to resurrect it as a backup punch for copying tapes I use with my ASR-33 and thereby save wear on the -33's punch. The unit has serial and parallel interfaces on DB25 connectors but I do not have any pinout information for those. The serial one I can probably figure out. Unfortunately, the unit is a little more sick than "works OK" seemed to imply from the eBay seller. It has what I believe to be a power supply problem because as soon as you try to punch all eight holes with the front panel test button, the power LED dims and the punch jams, apparently from lack of umph to complete the mission. It could also be jamming to start with and that causes the power drop I suppose. In any case, looking for any docs before I open it up and start digging around. I have written to GNT without a reply so far. Chris -- Chris Elmquist mailto:chrise at pobox.com