how is it 'broken'? the only shafts that will fit are the correct ones or custom ones a 90 has a 91and a bit inch wheel base,a disco has a 100 inch wheel base
The right bit will cost you less than fifty quid mate, and when you've fitted it, remember to grease it every couple of thousand, it'll last much longer.
Changing UJ would've saved me the flange, the oil filter, a gallon or 2 of oil and an oil pressure switch, but you know, why fix something that isn't well and truly knackered?