Re:
Can't help a lot but I have a frame with what look the same lugs. Mines are fastback type. Looking also for some info the only I could find about it is that the number engraved (72 in my case) is the angle. No other mark on the frame like yours. Also we share what looks a silva brake bridge. Got some hint mine could be a Rickert but I've already discarded this option. Does your's have any "R" in the fork... ?