Matco MC-1 master cylinder question

Has anyone ever rebuilt their Matco master cylinders? I'm bringing my baby out of a 10 year slumber and I'm starting at the ground up. Tires and calipers are done, but one master cylinder was sticking. So I ordered two rebuild kits from Matco. Everything looks straight forward except for gluing and sanding a buna plug to the end of the shaft. They are calling for
1/16" +- .005" below the edge of the shaft and you have to keep it flat! Will this be the odd job that finally puts a mini lathe in my workshop? Or has anyone done this chore before?
Thanks

I rebuilt my Matco MCs by replacing the o-rings with new rings from my Harbor Freight universal o-ring kit.

No facing, sanding or gluing required…

I thought about just changing the orings myself. The kits were cheap enough in aviation terms, so what do I have to lose?

If you don't replace the rubber your calipers can get stuck, and you have to take a 1/4" wrench out on some gravel bar and crack the bleeder to be able to get back out of there. Also the rebuild kit requires a special glue for the rubber your talking about. I think I just used a piece of sandpaper to get mine to 1/16 they called for.

I did mine by hand and they worked out fine. I'm sure using a lathe would be super, but it isn't necessary.

Yes, they call for Loctite 380. I found a small tube, instead of the $40 one ounce bottle, at Midway gunsmith supplies for just a few bucks. I guess if I can lap the injectors on my truck I can do the same motion with the buna plug.
Jay