Hello! I want to join in the discussion.
First, I wanted to thank all the participants for the discussion.
Indeed, there are quite reasonable points of view on the subject.
Fears and suspicions are fully justified.
But new information is constantly appearing, perhaps someone will be able to
change or adjust their views.
I found one lot with this master, and later I will show my subject with a similar hallmarks.
"A parcel-gilt silver tea and coffee service maker's mark Nicholls & Plincke, wiht the wor(k?)smaster's marks of
Jonus Auvin, Anders Long and Gustav Sohlman, St Petersburg, circa 1878-1879"
The lot was sold on June 1, 2015 at one of the auctions. There are no hallmarks.
The state and appearance of the service you see in the photo - it's excellent, mint.
I believe that Sohlman performed the main part of the service (5 items -teapot, a coffee pot, a sugar bowl, a cream jug, and swing-handled oval cake-basket), because he alone was by that time (1878-1879) an active master. The tray and small accessories belong to other, earlier masters (Auvin, Long).
General gilding was carried out either by workmasters of Nicholls & Plincke, or most likely also by Sohlman.
Unfortunately, there are no hallmarks, only guesses.