CMSNL had those in stock. I bought a couple earlier this year Al . You can bet if CMSNL have them then Fowlers can get them too
I'd like to bet Partzilla have them in the US too.
I buy taps on a pretty regular basis and salvage bits off them to make good ones up and in the last one there was a mint filter.
Usually they're gone or mashed.

Not even a photo on CMSNL, Dave!

If it's convenient, would you be able to post a photo of one? I might try and get a couple made up from the mesh that I've got.

Thanks.

Will do Al.
I just checked and they've removed the pic as they don't carry it anymore ( or nil stock )

 
Number 10 ,fowlers of Bristol. I'd like to bet that would be the same item.  
 
 
 

Thanks Dave, much appreciated.

Looking on fleabay, I wonder if those pipe screening mesh filter bowls can be adapted........? 

Update.

My mate punched and shaped a suitable sized hole in the gauze that I already had and fitted this. Not as good as the original part and we lose the ring at the top (bottom?!), but hopefully it should do the job.

Photo attached.