Derailleur is 10 speed Shimano 105
Sounds like it's not worth the bother.
I'm basically toying with the idea of upgrading my Croix de Fer to the
Shimano RS685 hydraulic disc brakes.
The shifters are 11 speed.
Looks like if I want t do that I'd need to buy a new wheelset as well.
The brakes/shifters are £383 at
Evans.
So plus another couple of hundred £ for wheelset, cassette and chain (and maybe a new rear derailleur required as well). Probably £600 in total.
That's quite an outlay, not sure if I can justify it.