Yes, but how much is it going to cost you if you get a leak? Also, you use an open ended spanner to undo the bolt mounts, not a socket or ring spanner.
When I did mine yesterday, one was on the verge of leaking, and with the seal ever so slightly disturbed it started pissing fluid out. You said one looks new which means that the other has leaked and now the other is older than that one, what do you think happens next?
With jobs like this you don’t pinch pennies, I had the box off my car yesterday so we changed the clutch, pressure plate and clutch release bearing. Now the clutch looked like it could have done another 90k Miles, but for £60 I knew the clutch was going to be as good as new.
For an extra 20 quid you could have had complete new rear brakes, now you’ve got manky cylinders that may or may not last you through the year and because you didn’t just replace everything, you’re going to have to take it apart again! False economy at its best.