cartridge

Hi All. We have a Bristan Shower in our en-suit which over the last year or so has become more and more difficult to turn off. When new, the water shut off with the handle at the 12 o'clock position but now you have to turn it, quite forcibly, to about the 2 o'clock position to get it off...

Its been dripping for a while so I'm going to start thinking of fixing it. It's about 10years old, you pull the lever right to turn it on and forwards/backwards for hot and cold. Does anyone have an idea if it could be fixed and what kind of washers or inserts it would have inside it? Thanks

Hi all Sorry if this is a daft question, but is there any chance someone could help us to identify the cartridge in the pictures attached, or point us in the right direction? I'm not well enough to replace the whole tap but can replace the cartridge, and unfortunately I can't afford £60 +...