Thanks to the interested Sèvres connoisseurs who contacted me to point out the slight problem with the following 'revelation': some-one else has already made the same 'discovery'!
10 years ago, David Peters published 'Sèvres plates and services of the 18th century' (2005) , in which he clears up the previous discrepancies about this artist & his mark. I'm pleased to learn this; it's like being at University again, with a master supporting my hypothesis!
The lesson here is : do not believe everything you read on the internet; there is a lot of 'junk' out there without academic support. I'm just pleased that this post, although incorrect in describing a 'new' discovery, is still accurate & a useful description of how a researcher can still discover fresh insights into this fascinating field.
Maybe next time I will be first.....
Paul Rosenberg, April 2015.