I guess this is one of those parts of an A model rod that you normally just go and buy. Nice shiny chromed rods with threaded ends that you just bolt up and adjust as necessary to get the radiator set right.
I decided to make my own as I did not want to see lots of threaded rod at the ends and wanted a different look at the firewall end. I bought a length of 303 grade 8mm diameter stainless steel for Aus$7. That gave me 3.2 meters to play with. More than enough for two rods.
303 stainless is supposed to be "free machining" so I chucked it up and put an 8mm thread on it. I'm no lathe pro, just teaching myself as I go, but it turned out ok. I put about 25mm of thread on the radiator end of the two rods.
Nothing special to see, just a thread. I will use stainless nuts of the same type as shown here.
At the firewall, I will turn up some suitable aluminium brackets, to replace the standard A model brackets which are bolted on. Mine will have no visible bolts.
At the radiator, aluminium covers for the nuts will be made also. I tried two types. I think I like the short one the best.