I don't have a 519, but I figured some of the members would :)
There are several listings for 125 ohm GR (search for "GR874" but most sellers don't know the difference between 125 and 50 ohm connectors).
174325617026
363163812256
222979950687
223426804340
161839191197
333654464808
Unfortunately, I think someone got the adapters Dennis is referring to (don't see them listed).
Better luck next time!
