Hi Mark, from another midlander -
'Proops Brothers' Fleckney Leicester were/are my local go-to stockists before Covid struck - if they are still in buisness?
they attended model engineering exhibitions selling tweezers etc along with the likes of Chronos, Shesto and Blackgates,
or Axminster Nuneaton.
Guessing the above may have been the suppliers of your rubbery dud's, a thought - have you tried forseps?
much stronger and available in all manner of weird and wonderful styles, with useful clamping facilities.
Downside I suspect the top quality geniune medical grade you're looking for will be expensive, if available to the general public.