Findlater's Royal Prestige

[Pictat]

I have a bottle of Findlater's Royal Prestige (Dark green not Red) stating that it contains whiskeys of 1939 distillation. I only see the red porcelain decanters when I do a web search but the blue bottle only seems to appear as a miniature (which mine is not). It is unopened, before I open it and enjoy (hopefully) I was hoping to get a value (which might make me more of a mind to sell rather than imbibe )
Thanks

[Archer]

Only ever seen dark blue or red. I think they sell for around £50 -£60 at auction