first check that the "old" BB with the crankset you intend to use gives you the correct "chainline" distance measured from the C/L of the seatube to middle of gap between the two chainrings (on a double) if that checks out then you can shop for a replacement BB unit with the same spindle length. (read this handy cheat-sheet from Sheldon: https://www.sheldonbrown.com/chainline.html)
Don't rule out a Shimano BB (made by Tange, usually) if you can find a low-mileage say UN-52 or better, Shimmy had Ital units offered in many models for many years.
Here's one on eBay that is oddly a "Deore" but if the seller lists it correctly it has correct shell width (70mm) and threading (24x36) for a Ital shell...but be advised that MANY Ital-threaded Shimmy BBs have the Octalink spindle, just to raise your hopes and then dash them!


this one is $59 or BO and it's a 116 mm square-taper (but JIS, I'm sure) spindle: https://www.ebay.com/itm/157115252720