its reynolds 531,although it never came stickered up,i did contact Ribbble to enquire why but that was 20 odd years ago and i cant remember the outcome,but im certain it was purchased as a 531 cyclocross frame,id like to keep it and build it up but weve reached 16 bikes in the garage and Mrs R is getting the hump!!!!hardly a mark on the frame,if your interested i can send more detailed pics ( you could always send a pic to
ribble to validate they would have built this from its 531)
Gary