Yeah, kinda my thoughts also. I have one Cub that smolders a little but still runs well. It may need work sometime in the near future if I can't clear it up with a Seafoam treatment.If you're working heading toward a rebuild due to low compression, use the high-compression pistons.
If your compression is good, I would focus on a complete tune-up and valve adjustment timing setup to squeeze as much out of it as possible out. If you are a risk taker, you can up the max RPM 2100-2300 to closer to the rating of the later C-60s in the numbered Cubs for a bit more HP but no change in torque.
From a retun on investment perspective ( time and money) , the second option is higher.