DuoFast CN350 Cylinder Seal

25+ year old DuoFast CN350 framing nailer with a shattered, worn out, Cylinder Seal. No OEM parts available. I've purchased two from EBay Vendors and both were garbage--their seals blew out of position in fewer than 10 nails. After that, they wouldn't last one nail. Printed this based off of measurments I took from the gun itself and the EBay seal I had. So far it's done 70 nails w/o problems. Mine came out much stiffer than the EBay seals--so much so that I had to boil some water and heat it in that to soften some before installing--perhaps that's why this one is holding up. Work in progress so comment with your results if you try it.