First I am not a cuemaker. Here is a picture of an 86ish meucci original with the 5/16-18(top)...A 1989 Sherm(middle)....And a 1988/89 Schon(bottom)...Id say its definitely not an 18 pin. When I compare the Sherm/Schon they are very similar and the Sherm shaft fits the Schon. My Sherm is...