I'd rebuild it.
It's easy & fast enough while it's out, but when it goes in rebuild will be annoying if a problem shortly occurs.
Save the old cylinder! The easy way on hydraulics (which tend to sort of start getting bad before becoming awful) is to save the old one, when the new one starts going order a rebuild kit for the old one, rebuild the old one, swap it onto the car, repeat. Downtime is reduced, especially because of problems that crop up in the rebuild, & the most dangerous time for older cars is when they're immobilized for repair.
This strategy of keeping, rebuilding & swapping is fast & very effective at keeping the car on the road. It also makes it so you can watch for & retain quality OEM spares as opposed to some later ones of lesser quality. It does result in owning 1.66666 cars of that model, but that's what file boxes & shelves are for.