Were these machines also used for a vacuum chamber/cold trap application?

I service also Polycold at a client and the gas costs indeed a fortune. Theyu have special top-off cilinders but even then, filled with small gold particles I think.

We once had serious troubles with a Polycold machine and a technician from Germany had to come.
He had a book with him with sevral pictures while they're were building a Polycold machine in the factory.
The gas mixs consists of 5 different refrigerants. Helium was the final ne, R114, I forgot the others.
But I found several autocascade gas-mixes on the net (patent databases)