Yes indeed, the Unicom for self announce traffic coordination is used.
131.425 is for jump operations and ground ops such as fuel orders.
Try the weekends.
You guys gotta quit teasing me. I did my last jump at the 2000 World Freefall Convention in Quincy IL. Now I'm getting the itch again. Started in rounds and finished in squares. I'll bet none of you remember round parachutes.