Cactus Jack was a bull born in the wrong era. He was be hotter than a $5 pistol if he was alive today. He was a very moderate framed bull that was super complete and sound made. He is the sire of many excellent cattle, including GFS Creole, who sired the top selling bull at the recent Iowa Beef Expo at $11,000.
I would check with Harold Good at Barnard KS as he was one of the main owners. The bull was syndicated as well and he may be able to give you some leads if he doesn't have any semen. Another possibly is David Jett, of Jett-Gardner Cattle Co, Laverne, OK. He bred Cactus Jack and he may be able to help.