Hmmm the problem is that almost all the european manufacturers put their logos somewhere and this thing has absolutely nothing. When I saw it I thought was english or french but the italian BB kind'a mislead big time. Is not japanese, again the BB shell.
My best guess based in the seatpost diameter and BB shell is that the bike it is a low end italian or french brand from back in the mid 60s. But the cable routing doesnt make any sense... low end doesnt have that cable routing
Next option is that the bike is a custom modernization of an old european brand and the cable routing was added later on together with the chrome work, chrome stuff 30 years ago was piece of cake and not that expensive.