68mm Italian Square Tapered BB

I have a frame which has a 68 mm BB shell, although its Italian threaded (normally for a 70mm shell). It had a Shimano Octalink cartridge BB, which worked because the adjustable cup slid over the cartridge and would adjust, possibly to work on any shell up to 73 mm. I want to swap the BB for a square tapered one for a campy crank. Any thoughts on where I could find a square tapered (ISO) BB with Italian threading that would fit a 68 mm bottom bracket shell?

theres loads on ebay usually

miche primato - £10 from anywhere

But does the miche primato come with 68 wide shell in italian threading? I have for sure not seen one :)

A 70mm BB would only stick out 1mm on each side. Not a problem, especially if it's adjustable like a Miche.

Use an old Italian b.b lock ring on a 70 mm bb to take up the slack. Problem solved.

2 options

1. add spacer(s)
   
2. get a cup and cone type bb, swap the spindle from a british hreaded bb
   

But does the miche primato come with 68 wide shell in italian threading? I have for sure not seen one :)

ok, based on the fact that italian threading = 70mm, what makes you think the shell is 68mm deep?

you're talking about 1mm either side, which is not much more than the thickness of the paint on the cups, right?