Hi there! Few weeks ago I purchased a frame of this legendary brand! The number 8129 is indicated on the frame and the fork, and the Reynolds 531 mark is indicated on the plug stem as usual! I would like to identify what exactly this model is and what year of production, because the frame itself is of a non-native color, but in tubes at bottom bracket there is red paint, so the original color is red! Hope you can help me! Thanks!

P.S: Can't attach url, cause I'm new here :/