Nic; your frame may have been back to the factory to have the later disc eye fitted at some point. I seem to remember a few coming back for repair and refurb which could include later updates if the customer required it.
Time to reopen this thread and throw my Pace in. Bought the F&F last year from Kult Friction, who describes it thus;
"A one-off built frame - 1992, the frame doesn't have brake pivots, but four bolt magura Hydrostop mounts and no rear brake cable stop on the wishbone or brake cable guides on the frame (a la RC100), It's anodised champagne (almost the same colour as the Pace extruder chainrings) and has no frame number! It was a special sorted by one of the guys at Pace bitd, Possibly Adrian.
The forks work perfectly (Even still running on the original '92 elastomers :shock: ) and have been running like so since day one with an outlandish 65mm travel IIRC, All thanks to slightly longer stanchions, extended elastomer stack and longer damper rods, Which in all fairness is all there is to them"
No double external butting on the frame, so possibly an F1?