Just to clarify, I don't believe the original arm on the Paris is exactly the same as the Jelco 250ST. For one thing, the original arm (at least on my Paris) was an Audioquest PT-5 (made, of course, by Jelco), but it had fluid damping, which I understand the 250ST does not have. Not sure if there are any other differences.
I've replaced the original arm with a Sumiko MMT (a forerunner to the Jelco 750), and I am very satisfied with it. I really like the ability to change out cartridges, with the removable headshell. (Note the geometry of the MMT and the Jelco 750 are not the same.)
-Bob