Every part is still available for one, you just may have to spend a bit for them. Either saw will likely have a Walbro SDC carburetor so kits are easy to find. Both OEM and aftermarket fuel lines are available, seals are standard items, rings are generally available for less than $20. As long as the cylinder is not scored badly the saw can certainly be made to run again. NOS mufflers can be found but sometimes they want $50 for one.
The Pro 10-10 would be points ignition, most of the Pro Mac 10-10 (and other Pro Mac saws) were electronic ignition except for a few very early ones. I don't mind working on a points ignition saw since I can troubleshoot every single component. Some folks prefer the simplicity of the electronic.
Mark