Looking for some advice on how best to proceed with this leaky concealed shower....
see pic @ https://db.tt/xhjUzA9N after I had broken into wall to access back of valve

i) background
o Shower is a v old aqualisa 200 ... with the valve concealed in a breeze block wall.... Gravity fed, with all 22mm piping (see picture)
o Wall is about 4 inches total width (with plaster etc).
o Shower was great until it started leaking... down the inside of the wall.
o I have determined that the leak comes from both internally to the cartridge itself... but also between the cartridge and the valve body as the threaded inserts in valve body have snapped preventing the 4 screws holding the cartridge in cannot be sufficiently tightened.
o As can be seen the visible parts of the shower is now also looking tired.....

ii) The plan is to refit the entire bathroom, budget/health allowing sometime mid next year. In the meantime I'm trying to think of the best way to get a working shower.

iii) I could try Repair / refurbish existing
o A new shower body + cartridge would be £150+ from aqualisa... and I'm not entirely sure that the current supplies match my originals re centres and 22mm piping
o Visible parts would still look shabby

iv) I think I would prefer Replace
o Given the aggro with leaking within the wall I'd prefer an exposed valve in future
o Is there an easy way to bring the 22mm inlets out into the sower area as 15mm so that a basic manual shower / bar shower can be attached externally
o there is little room to work on the 22mm pipes without taking the entire wall apart, though once the old valve body is removed they might push together a little to be more like the std 150cm

Any Advice?
thanks Mark