I took off the original post and images.

Looks like an indexing problem on the site this morning. My comment was regarding the Vietnam-era river gunboat.

CommodoreH, a fantastic workshop. I envy your toolboard, handtools easily located. "A place for everything, & everything in its place." A lifelong goal of mine, never achieved tho.

The original post seems to have disappeared , so I can’t really comment. I see an image of two objects, but only the comments messages come up when I click on it.

I am going to get into trouble if this thread wanders into pros and cons of hearing aids.

The unit looks similar to mine, I had a bizzare choice of colours but quickly chose ones that matched my hair where it still shows.
Roy

If they are hearing aid inserts and I have seen similar, they are about 5-6mms diameter.
Ihave a friend who has them and I was going to ask (NHS) Audio dept if they were options as they look like they allow a bit of airflow.
Roy

Memories of dear Martin555 (RIP) and his yoghurt pot and ice cream tub creations Rod.
"Every item that I consider putting in the garbage or into recycling is something that I look at with an eye towards using it in one of my hobbies."
That's why I'm 'up to me neck in muck n bullets'. In danger of being called a 'Messy'😁
😎

Good one Ron 👍😂🤣
Nearly fell off my chair laughing😉
I couldn't see that as a radar antenna dish, proportions all wrong re the 'lump' in the middle, where the receiver detector/waveguide would be on a real antenna and the collator which collects and directs the signal to the central detector is missing. In TX mode it would project the signal to the dish to be collimated and transmitted.
Certainly no antenna I'd ever seen be it on ship or land, and believe me I've seen some.
If you want to use them as antenna parts best I can suggest is a ground plane at the base of a VHF monopole antenna (e.g. VHF Marine Mobile), inverted disk, i.e. rounding down towards the edge.
I was about to ask you for the dimensions and where you found them.
My first thought was parts of a model car wheel hub.
But you might be better off having them gold plated and made into a pair of cufflinks😉
Cheers, Doug😎

Every item that I consider putting in the garbage or into recycling is something that I look at with an eye towards using it in one of my hobbies. I recently visited a ship modeler who builds RC combat ships, the ones that actually fire BB's at each other, and he had used bottle caps inverted to form the armor around gunners. I keep plastic containers from ready to eat food, if they are clear and unscratched I use them for flat windshield glass, if they are too curved I use them as Parts trays rather than buy something new from Dollarama

Google "image of radar dish antenna" & you will find something similar.

Any opening in the surface of the dish must be smaller than 1/10th of the wavelength of the operating frequency of the dish antenna. Hence those elliptical openings probably disqualify them for use as modern radar antennas.

In WW2 the vertical curtain multiple-dipole arrays that guarded the southern coast of England operated around 27-28MHz which is now the 10m Amateur Radio band worldwide. Those curtain arrays had huge spaces between elements but functioned as a flat sheet antenna becuz they had openings less than 1/10 wavelength in width/height.