Hello Andrew
I don't have a 275, but the type of removable tubular table legs, with a choice of recessed or surface mount sockets that I assume that you are referring to, used to be sold under the Desmo brand name as long ago as the '70s.
Over the years, the idea has been widely copied internationally for both the marine and caravan market, in various materials.
If you search Google and Google Images with "Desmo table" (& leg, & base), you will find many variants, often described as "Desmo type", some in alloy, some in powder coated steel , some in stainless, some with 6 hole fixings, some with 8 holes eg at Norfolk Marine, Midland Chandlers and even on eBay.
Hope that this helps you track down the right variant.
sincerely
Geoff Sheddick
Parker 27/146 "Stroller'
Geoff Sheddick
Parker 27/146 "Stroller'