Weird. I've got a similar bike that I have not been able to identify: triple windowed head lug, full 531, scalloped seat stays, Campagnolo dropouts, oval fork stays, windowed spearpoint lugs on the inside of the fork, same fork crown. The only thing that I know is that it must be late 70s, early 80s based on the parts hanging on it.
The only thing that is obviously different is the seat tube lug. I'm pretty sure mine is not pointed.
As for my bottom bracket, it was damaged at some time: an oaf brazed crappy looking steel reinforcements on it. I'm imagining that the bb shell was a drilled version of yours.
Nice bike, whatever it is.