+1 this. Despite the 70mm shell, it is English thread, not Italian. One of the cases demonstrating the unreliability of using shell width to guess thread spec.

If the current bottom bracket is in reasonable condition, why bother replacing it? If it does need replacing, look for a code on the spindle like "5N" or some such. Find a replacement spindle with the same code. Chances are, the cups will be OK; spindles always wear out first. If you do have to replace the whole thing, finding a suitable modern cartridge can be a matter of trial and error. Most English thread cartridges are designed for 68mm shells and may not work in a 70mm shell. A 73mm MTB cartridge might work with spacers in the proper places to get a reasonable chainline. Good luck!