In general, many many reproducers are not restored correctly, when I used to go to the Union show, I would ask to hear a machine, it was low volume and tinny, and these were supposedly rebuilt. I know two others who are very good at reproducer rebuild, but most are not good at all. I do local reproducer rebuilding of Edison reproducers, but I do not do mail order, I also do Victor Exhibitions, and No. 2 . In general all moving parts must move freely, the gaskets must be soft, the diaphragm must be centered, and the retaining ring, just seals, and makes it air tight, any more, and they sound tinny, and low volume.