Dig it out indeed! Hah!!! :tsk: John, I suspect it's just air/damp affecting the metalwork.
Your date estimated matches my initial thoughts as well, thanks. :thup:
Hazel, thank you! I'd not even considered a maker like Walsh - I've been trawling through catalogues on glas-musterbuch.de and Google images and my own books and reference stuff, seen lots of lamps with and without shades (but mainly with matching shades) but none that match this one. :cry:
As we don't have the shade for it I'm seeking one that will work with it once it's been rewired.