OK - White Knight brand Red Oxide Spray Primer looks the part and adheres as you'd expect to a washed and cleaned HDPE milk container - badly. Camera is not working so I can't post pics, sorry.
Done! Thanks RT. I just googled the brands I know are stocked locally and found one readily available in Australia - White Knight Red Oxide Primer Spray. AU$18 for anyone down here who is looking to add that extra bit of authenticity to their lid.
I'm planning to do some testing on an HDPE milk container tomorrow and I will post the results.
Anyone know what sort of Red primer is currently available and accurate? I just checked out my local hardware and paint shop and all the spray primer was in grey or white. Plenty of red spray, but not primer spray.