Help recognising serial number TN0109
 

Morning. Cant post any pictures yet but Im wondering if anybody can recognise the maker of a Reynolds 531 Designer Select 1980s frame I have purchased purely by the serial number. Not a hugely exciting frame but its well made and I believe the frame is British built. (im in the UK) if not British then perhaps Benelux. The frame seems to be in its original Bianchi green but the serial number doesn't match their patterns.1900g for bare frame and 698g for forks. Campagnolo dropouts 68mm BB shell. Came with Campagnolo headset and seat-post. My one clue is the serial number stamped on both BB and forks. TN0109 Any help recognising the numbers or deciphering the serial number pattern would be much appreciated. Jonny