I haven't heard of anyone doing this process in years, but in the late 50s, when I was learning about automotive engines and rebuilding, there was a process called knurling the cylinder, to enlarge the existing piston to fit in the oversized cylinder. This would not be difficult for anyone to accomplish with a lathe and a knurling tool. Practice on a scrap automotive piston, until you have the amount of knurling required, then go for it.
This somewhat describes the process from the Home Machinist forum:
Here is one example from youtube, that shows just knurling the most worn portion of the piston skirt. This is being done with the small knurling wheels, like the ones I have ( just to make the point that it is common for almost anyone owning a lathe to have them)
I also checked, and piston knurling tools are still available. For just one job, I would use the small knurling tool that any machinist would have available. I have a knurling tool, and use it for knurling things like tool handles.
Lots of them available on epay, just do a search for piston knurling tool.
Here is another excellent article regarding an engine builder using this process on his ProStock and ProMod nitrous engines. When you think that these guys are adding 200 or so horsepower, or more, to these engines, that has to add confidence in the process.
Bob
Edited to add more information.
I hope this is helpful