Strange logo on the frame
I'm thinking it looks a lot like the Hans Lutz logo:



German manufacturer, ex racer... 

I'm not sure he made just lugs, for Bianchi at that. So I think you're correct about it being rebranded. Silly really, the Hans Lutz I've seen is nice stuff!

Note the color of the frame too, very similar to that pictured. I can also vouch that the bidon holder mount holes on yours look exactly the same as those on the frame pictured here.