You should jump over to the Go Go Varmit board and ask that same question. Bill Delmonte (who lurks over there) /ubbthreads/images/graemlins/smile.gifprovided sounds to Bill Anderson and knows that caller well. He and Bill were business associates.
That caller was the very first that I am aware of to usher in the age of rechargable callers. I discounted it's viability due to the use of a motorcycle battery(heavy and leaked acid)that had to be vented with a hose hanging out of the caller. That caused quite a few problems with acid getting on truck seats and floorboards.
I severly underestimated the consumers desire to get away from using D-cell batteries. That caller got pretty well established as a regional product before Bill Anderson died of heart complications in 1987, the same year my father passed away from heart trouble.
That caller may be very desirable by some of the collectors. You just don't come across them often. It should sound fairly clean and may have some damage due to age or storage conditions. I would love to see a picture of it if you could post one.