Thanks for the feedback – I am going to use it for cross this autumn. I am fitting a Paul Chain keeper – it's on order. I will drop Neil a line and see when it was made. The chap I got it off was on the Orrell MTB team in the 90s.
Here's my Neil Orrell cross bike; just got it back from being built up by Cadence in Bath. Got the frame off eBay and just put together what was in the garage mostly or second hand. A few new bits (bar end shifter, 9 speed cassette, brakes...).