need to rehang pocket doors from 1960's

Is the old track too narrow or too shallow for the hanger's wheels, the door is now too long when hung on the new hardware or what exactly seems to be the problem?

If the old sliding track no longer works for the new hanger wheels, I would just replace the track. It is a very inexpensive aluminum extrusion profile that might only set you back $20 or so but will be compatible with all the modern hardware. If you bought Stanley hardware, I'd recommend their tracks, too.

If the door is now too tall, you'd need to trim it so that  the door height is 2-5/8" less than the finished opening height (dimensions for the common Stanely 150lbs pocket door hardware). 

It is seen as an eco-friendly product to install a PVC door curtain in your facility. Because aside from giving easy access to both people and equipment like forklifts, it is also very effective in keeping out unwanted items such as insects, draughts, dust, and also noise. It can make one room safe from the contaminants that can be found just outside its door.