551, 951 and 428 Large Trailer (1948-71)

I finally found an example with plastic hubs. It took me some years so I'm very happy with this version. Still looking for the version with blue supertoys hubs. Can any member tell me if another version is missing from my above group of trailers?

The answer, Jacques, to your request: this example with yellow hubs has the grooved Dinky Supertoys diecast hubs. I presume the only plastic hubs on the Large Trailer are in red. Correct or not? Kind regards, Jan

Thank you Jan, I just wanted to make sure.