One of the challenges with RR Armoured car pictures is that many (if not most) are mis-captioned. They were "All" used by T.E. Lawrence. And one desert looks like another. So over the years, there is a massive amount of historical bovine scatology about what pictures are what. It's part of the project my friend and fellow-military historian have been working on to organize and get some realistic research behind the photos. See our Blue Mist article from 2017, if you have not seen it already.
As I mentioned, I highly recommend Col. Barrass's book. He probably did more research than anyone on the subject before his passing. Eric was a great gentleman and did a lot for the RR community.
Here are some photos. A number of them are from the NoPerForce (Northern Persia Force) from right after the war... on the Soviet border. An interesting time for the Armoured cars, but I think most of them were 1914 pattern that were left over and moved in. But Eric's book would shed more light.
Here are a few pictures. There is some confusion over Wedding Bells II... which *may* be the Tank Museum's armoured car? Wedding Bells 1 was a very early armoured car.... predating the Admiralty pattern. I've added notes where I can! Which isn't much.

This may be one of the most relevant pictures. According to caption Iraq in the 1920's but take with a grain of salt.

Note aired-down rear tire.

This is NorPerForce picture. But these seem to be 1914 pattern.

I think this was the Flying Fox, destroyed in Persia as part of NorPerForce

More from NorPerForce 1920.

This was from 1940, also Iraq if memory serves. By this time, the bodies may be on Ford Truck Chassis. Late in life, the Ghosts were simply too far gone and too much to maintain. But the armour was still useful and it was transferred to Ford chassis as they were likely the same wheelbase.

May be from the same time as the above picture. Note the wheels.

This is one of a couple of confusing photos. Because this was also captioned (later) as being at the Tank Museum. But I don't think it's the same armoured car that is with them presently. At least the registration is different... even if the cars are remarkably similar. Is Wedding Bells II the same car that is at Bovington today?

This is a post-war pattern car with a Lewis gun... but note the very late wheels. Again, possibly late '30s or '40 in Iraq? Not sure.

Unknown photo of a post-war pattern car.

Got enough spare tires there, guys? NorPerForce 1920. But this looks like a leftover 1914 pattern car...not a new one.

Another NorPerForce photo that definitely looks like a 1914 pattern.

Again.... looks like 1914 pattern in use post-war.

This is the Wedding Bells II picture from above... but with a different caption saying this time that it is at Bovington. Is Wedding Bells II the car that is currently at The Tank Museum???

This is the original Wedding Bells... a 1914 pattern car that was all over the place in WW1 and then ended up with the above India Pattern armour on it... and in Banglore. I think that this car is now gone. But it had an impressive battle record and was 'everywhere' in WW1. Is it in India, still?
That's it for now... hope this helps with your build, Phil!
Cheers,
RPR