Only one of the seals seemed similar, and I can't quite recall which one, so I only replaced that one and kept the other seal as original.
I did my spare cylinder (or at least the piston, the cylinder still needs a cleaning inside) yesterday, and I managed to fit both seals. One of them was a combination of an o-ring and a seal, but it fits perfectly, and I'm certain it will last at least a couple of driving hours...