Search for Viner Sandringham pattern

I have been trying to find/add pieces to my late grandmothers E Viner “Sandringham” double-struck pattern sterling flatware. Have found a few things off Ebay, Etsy, Ebay UK and Ruby Lane…
Does anyone happen to know of any well stocked flatware dealers or where else I should look? … been looking for 6 months and watching live auctioneers but having a hard time finding.

Trying to expand a 6 place settings to 12… not too concerned with matching the year as at some point I’ll give each of my 2 kids a 6 set each so will become 2 separate sets again down the road -but would like to have the 2nd six set be somewhat straight in year… whether it be 1930s, 40.s or 50s… Open to individual pieces or maybe a whole 6 set.