Drawbar piston O ring

I need a new O ring for my drawbar piston on a VMC-15. Got a new one from itscnc but it's wrong; it's too slim.
Mine is 1/8" nominal; .139 actual cross section.
The one from itscnc is like 1/16" nominal .
Measures to be maybe a 262 trade size? Anyone use this or possibly 263 or 264?

The trade size is 247.
.139 CS x 4.609 ID. Fadal part # is HDW-0170.

That's way too small.

Whoops. Thats for the auger on a slant.Size 263 looks closest to me.

I have a spare along with the plate if your having trouble getting parts