See if you can find the pin-outs / wiring diagram for the welder.
If you can work out what each pin does then it's easy enough to see if any other type of push-pull torch can be used.
You can then either source and fit a matching plug to the gun, get a plug to match the welder and a socket to match the gun and make up an adaptor cable or, (sometimes the cheapest option) fit a matching plug and socket to welder and gun.