NOS Nathan Air Chime P1

I have a nos sand cast P1 that was never installed on a train, only had a bolt on adapter to test horn. Any idea on a value. Will post numbers and pictures when i get some better pictures. It has the original back cap and says pat pend on the one side not pat pinned so appears its the early generation. Looking to sell so if your interested or can help with value or a collector thats interested let me know.