is it hard to find a tailshaft for these bad boys?

If memory serves,you can fit a 1200(non ute)shaft,the ends are the same..H145,same gearbox end,just can't remember if i have changed the length in the past,even if you do it's no
big deal really.

Anyway you gota remember 99% of B10 tailshafts will have stuffed uni's by now anyway...so best get one made and save any grief.

so should i just go to driveline services an ask for them to make one?
or could i get a ute talshaft cut down?

If you have a B10 one(stuffed or otherwise)take it to driveline and get them to rebuild it.
The ute shaft will fit the box but the back will have to be cut off and the smaller coupling welded on and balanced with new uni's.

If you have no shaft,you will have to measure the length req'd for the shaft and give this info to driveline....so get the car on stands and stick the ute tailshaft in the box and hold it up to the diff flange to work out how much you need to lenghthen or shorten,make sure you give yourself about 5mm of clearance inside the gearbox.

I just got one made for my sr sedan. All I did was measure from the face of the spline to the flange face and rocked in and gave them the dimension and told them I wanted an sr on one end and a commodore on the other and they did the rest. I imagine they should be able to do the same, although with something that "old" it would be easier if they had one to copy

I also just got one made by Sydney Driveline Service. I took them an old shaft hoping that it would just need to be shortened (at $150)... but as soon as they looked at it they said no chance, the unis were dead, welded in and non-serviceable. So i got a new one made - cost $400 (ouch).. on the up side, the unis are now serviceable / replaceable and you can pick the diameter of shaft that you want (useful for me as I have serious clearance issues).... if any of that helps...