That may have been Gerd at SW Drums (who are superb).UK vintage traders may be your best bet?In recent years I would've suggested Nick Hopkin, but he recently ceased trading. I used to get mine from Classic Drums, but sadly Len Howe passed away over a year ago.You could try Tristan at Drumattic:https://www.drum-attic.co.uk/ or Rusty Drums:http://www.rustydrums.co.uk/or Jo Cox:http://www.joecoxdrums.com/or Orange Tag:https://www.orangetag.co.uk/Failing that, there seem to be a few brass grommets for sale on eBay

I doubt you'd find original Premier grommets, unless they'd been "cannibalised" from existing old drums. If so, the only other place I know here would be Simon John's Vintage Drum Show in Coventry, in October. Stall holders often have that sort of thing.

Got it, GERD from ST drums replied to me and said he only has brass ones but he told me the dimensions on the ones he has (6mm hole) and it is basically the one being sold on UK Ebay which is listed as “for Premier drums”, I talked to the seller. So I just bought some of the aluminum (silver) ones on UK Ebay. Thanks for your help.