My Cars: Historically, lots of BX hatches/estates in the 90s/00s - 16/19i/17td/19d Recent scruffy diesel n/a estate - "The Red Shed" - is no longer mine.
The doc should be able to tell you about any local specialists, though I do recall that Wyvern motors on the other side of the Severn was still doing work on all kinds of Citroens when I last passed it some years ago.
Back on two wheels and pedal power for the moment.