Already tried KMS - they were less than helpful. Took the old spring in to match it up with floor models, but rep in machine tools section said they had nothing like that.
As I said earlier the parts rep at Modern Tool was very helpful & he found one that is close (drilling centre hole larger & modifying my stop as new unit a bit larger diameter).
Thanks ALL for your suggestions.
Often wondered why Jet doesn’t sell their machine tools on this side of 49th parallel. I can buy hand tools (sockets, ratchets, punches, etc. at Calgary Fast & other Industrial suppliers but not machine tools). Have seen their machine line in US and these tools are very well made.