Not a good start to the day - originally I posted these words onto the other, related, thread - though that panel isn't opalescent. However, will leave my words as they are, and readers can ignore all or part as they wish.
I can see the reasoning behind the suggestion of Walsh, but having read the blurb on their opalescent 'Vesta' screened lighting panels, consider we can discount that source for this particular piece. Walsh's most famous series of opalescent panels was probably 'The Twelve Labours of Hercules' - apparently "a complex manufacturing process" - according to Reynolds, the majority of pieces are marked G.Sc.R.fec. - which is a reference to the fact that the designer was the sculptor Walter Gilbert, for most of these panels.
Not a good start to the day - in error I posted this onto the other, similar, thread - though that panels isn't opalescent - so apologies for the gaff, but will leave as-is for the time being, and will delete my words on the other thread ………….

The appearance and subject matter of this panel does appear to suggest a far greater nod toward Continental flora/fauna subjects, than the few examples of Walsh's panels in Reynolds book.
I did wonder about Barolac, but think they were Czechoslovakian rather than German.
GMB contributor Mosquito (Steven) is someone with a good knowledge of first half C20 opalescent - hopefully he may yet look in - though I've no idea of his current difficulties or restrictions in China regarding the pandemic.
I do like the look of these 'love bird' type panels - but then I'm a big fan of opalescent.
Ref. 'The Glass Of John Walsh Walsh 1850 - 1951 - Eric Reynolds - 1999...……….. and yes, it really does read …. Walsh Walsh