RN Combined Ops question for a display

[Phill Lockett]

Hi friends

Have to confess I know nothing on WWII RN Rank/Trade insignia.

I have looked on the forum and internet and confused with dating WWII or post WWII with Kings crown.

Are these WWII RN,if so would they be okay to go with a WWII combined ops FS?

Would these have been worn on khaki battle dress?

Would like to have a WWII Royal Navy title to go with it at some stage.

Thanks in advance

Phill