I'm wondering if anybody out there can recognize this bottom bracket. Its a type I've never seen before and no amount of searching the internet seems to turn up any clues. Its on a late 70s/early 80s Colnago that I've owned for a few years, but only for the first time recently pulled the cranks off it and found this. Its marked only with a "6L" on both sides (both sides appear identical), and has no lockrings. It resembles in a way an old Galli BB, with the tapered roller bearings, but the end of the bearings on this are visible and say "INA" "SCE 109" and "USA". The internet says INA SCE109 are needle bearings! The shell measures 69.5ish, so probably nominally 70mm. and where the cups protrude from the shell, they don't appear to be threaded. Here's a couple shots of non-drive side:


and here's the drive side:

Any help would be Greatly appreciated!