I built this frame up recently with some modern kit but it’s an ongoing mystery who actually made it in the first place. I’ve had 1 or 2 tidbits when enquiring elsewhere but no positive ID. Does anyone have any ideas? It’s Columbus SL and has Columbus dropouts, an English BB, Gipiemme brake bridge and Andrew Hague seat bolt. The BB shell is marked SR and has 117 stamped on the DS and R 11 9 on the centre. Does anyone have any ideas?