Note: I have a similar clutch disc listed, but with 10 splines, 1 1/4 opening, if you’d like to take a look. Up for sale is a vintage NOS in box clutch plate/disc by NATIONAL BUSHING & PARTS CO. This in NOS, has never been used, still in the box, been in storage since the 1930s. Part Numbers: Attached to the clutch is a tag that reads: NATIONAL BUSHING & PARTS CO. Stamped on the clutch is: A220. Printed on the box is: C4. Measurements: It measures 9 7/8 diameter, it has 4 splines. The center splined hole measures 1 1/2 across when measured deep inside the splines. Please do your own research. Condition : As you can see in the pictures, it is still in the box. I’m not familiar with this clutch disk / plate, but it looks to be in good condition. The outer disc is very smooth, with a few spots of discoloration. The top inner portion has some spots of pitting here and there. The back looks good. Please take a look at the pictures. The box shows wear from age. It’s still holding together, but not in good condition.