Hi Shaun,
You've got a thing even rarer than the daily 4x4!
The Rayton was pretty much the predecessor to all the european SUVs; pre-Range Rover, Cherokee etc.
Those guys had vision and were way ahead of their time; pity they were hopeless salesmen (and Fiat didn't share their vision, to their cost).
They also used commercial vehicle parts, which is why you're having trouble.

Which end of the tie rod are you talking about?
The outer (wheel) end knuckle is available, costs a fair bit compared to the 2wd version.
The inner end (bolted to the rack) is bloody hard to sort out.

As you don't have a chassis number that would make any sense, measure the diameter of the tie rod to reassure me that it's a 4WD rack.
I've been running a 2wd rack for a while now (including an African adventure), it bolts into the same place and doesn't seem to work any less.
But the tie rods are thinner.
Which means the brand new outside knuckle (I can't remember if I have 1 or 2) that I was carrying as a spare(s) are no use to me...

If it's a 2wd rack, which is not impossible as they're plenty tough and who knows what bits and bobs went into the Rayton, we could use the chassis number off almost any old Daily.

Shipping might cost a bit though. I'll find out once you tell me your rod diameter (oo-er)


Off to rummage and see if I have one or two.

Luke