I think you'll find that Airline pilots aren't particularly sought after for GA gigs even if they might of done it in a past life.
With modern aircraft being very easy to fly and the over reliance on automation, ex airline pilots have really struggled to adapt back to the complexity of operating light aircraft as a single pilot and many just don't make the cut.
Flying a heavy single or turbocharged piston twin is a strenuous exercise and sadly years of watching the autopilot have rendered most Airline pilots incapable of managing such aircraft again.