There are guys here with WAY more knowledge than me, but I'll contribute the little I know...

The seatpost binder bolt being placed at the front of the seat cluster is an uncommon arrangement. I don't know who else might've built bikes with that detail, but Bianchi did it in the 1940s and maybe into the early '50s. The pump pegs on the back of the seat tube are also similar to what you might find on some Bianchis of that period.

The hole on the top side of the bottom bracket shell is an oil port. I don't know exactly when those went the way of the dodo, but they were common on bikes built before the 1960s.

What's the size/threading of the bottom bracket? Is it Italian, perchance? (36 mm by 24 tpi, right hand threading on both sides of the frame)