Thanks lots of information for me to investigate! :0) The WMF was on the tray!

Both pots and tray are from [b]Wächtersbacher Steingutfabrik[/b], better known under their non-Umlaut short ‘[i]Waechtersbach[/i]’. The metal part of the tray however came from the German Kitchenware giant [i]Württembergische Metallwaren-Fabrik[/i], short WMF; the stamped WMF on the ceramic part stating that it was made for a WMF rim; the “Dec. 2104” addition represents the pattern code.

Such teamwork was quite common back then. While Waechtersbach sold such sets, they could not make the metal part, WMF made similar products but could not produce the required ceramics. The result was a symbiosis of sorts, leading to these item marriages. These could be sold as Waechtersbach or WMF, in both cases cross-refering and relying on the good reputation of the other. It is vital to understand that WMF was not seen as mere supplier but equal partner here.

Sometimes one and the same set was sold by both companies, merely differing in the used decoration; WMF also worked together with Villeroy & Boch.

https://www.rubylane.com/blog/categories/what-s-this/royal-vienna-and-the-beehive-mark-real-or-fake/

What is the WMF stamped on ?? The mark above the numbers is what most call the beehive mark !! It started as a shield mark for the Royal Manufactory in Vienna !! Over the years many have copied it in some form !! The link above will give you some information about the mark !! Since yours appears to be a raised mark and was made in the mold,,it is not the Royal Vienna mark,, theirs would be a blue mark hand applied under the glaze !! There are many others that have used this mark !! I did not find any that used this made in the mold method !!
WMF,,Wurttembergische Metallwaren Fabrik,, was a German silverplate mfr.!! They may have made the metal parts for this set !!