Please excuse me if this is posted in the wrong place. What I am hoping for is that someone can provide some previous history on my 1951 Rapide. I recently had cause to start stripping the engine after a death rattle on the way back from my local club. I assumed, wrongly, that the bike was fairly standard, but the further I get into it, the more non-standard it becomes. Lifting the heads, I found that the front exhaust guide was loose in the head. Thinking this was the source of the noise, I had this repaired and this is where the problems started. Removing the valves was the first issue, I couldn't find the circlips referred to in the book. This was because the valves have been replaced with Gold Star type valves and springs. The inlet ports have been opened to 32mm and gas flowed and the valve guide lock rings and guides backed off presumably to allow high lift cams (Mark II) to be fitted. The exhaust screw in ports have been replaced with stubs and the pipes fit over these secured by clamps. The rockers look nothing like normal ones, they are lightened and polished and have needle rollers in them rather than the standard pin ( a modification of dubious efficiency). I now discover on further inspection that the front big end has failed and the play in the con rod suggested an Alpha caged roller big end. Having shown the heads to Ray Elger, he opined that the bike, or at very least the heads, had been prepared for racing, as the modifications mirrored what he had done to his own bike, the intention being to get the engine to rev. He also informed me that the pistons were Hepolite and dated back to the sixties (and weren't very good apparently!). The front one is scrap as it has contacted the valves and a piece has broken out down to the top piston ring and I would have to replace both anyway to have a matched pair. I don't know what CR they are, but no compression plates are fitted; they may be 7.3 or 8:1. The pistons have STD on the top. The bike is a matching numbers bike, UFM RC/1/8678, VRM GUT723 ( I have a photocopy of the factory despatch note with all the numbers matching, engine, UFM and RFM and the crankcase halves also match). I did contact the previous owner, but unfortunately he could shed no light on the provenance. I don't have the buff logbook, nor did he. The bike as bought was fitted with standard Rapide carbs and adaptors, thus nullifying the effects of the head tuning. It has an electric start fitted, modern type clutch (not Vincent), a rack and centre stand, but is still running magneto ignition with ATD. I am hoping that someone may recognise the bike and/or the modifications and can provide some history. I don't anticipate that it will be famous or infamous, but I would just like to know more about it, since it will require a complete overhaul.