Catch spring for Morse 4300
 

Hi, does anyone know the part number for the upper tension catch spring for a Morse zig zag 4300 fotomatic 3 machine? I ordered a cs301 because it was advertised to fit, but it didn't and I was refunded. I also read a post here about the barrel size of the whole tension assembly, in which they state "The OEM tensioner is 21/16 " OD at the barrel mounting casting that goes into the frame."...I'm sure they mean 21/32" which is an actual fraction and is indeed the size of the barrel on my machine.
thanks for the help!