John - I'm pretty sure all the steering gear is as original, and there's no wear in any of the linkages and the box seems good too, so it's all set to go. The hub turning circle is limited by two stops on the brake backplate, both of which go to their respective limits easily with this set up hence my thinking (along with the fact that it all looks original and un-touched/bodged) that it's not been "tinkered with" as it were.
Just so's you know, this vehicle consists of a chassis and running gear only, it's been converted to a garden buggy with a tipper deck on the back, and will never see the road again - not legally anyway (I live in a remote single-track dead-end lane, so it might make the 1/4 mile trip to the neighbours!). Nonetheless, I'm lucky enough to live in a house with the sort of land that can make driving this around if not exactly a necessity, at least useful, and even though the 750cc engine is a sidevalve they still go pretty well, I reckon I'll be able to boast the fastest garden buggy in the county! That's one of the reasons I want to get the front brake working (see my other Reliant brake parts thread) as when I got it the front brake pipe was blanked off, braking being via only the rear hubs. I'll get the handbrake sorted too, as currently the cable has mouldered into dust.
So has the underside of the chassis too - in spite of no body I've still got a bit of a welding marathon to do in the next few weeks, much of it in awkward places too. Still, it doesn't have to pass an MoT.....
Thanks again for the advice on the oil, I knew someone would know.
Cheers!