Originally Posted by Helleri
... I hope what I have laid out here was not too much of a bore to read through and that it is at least somewhat helpful...
By all means, a wealth of knowledge being poured and, as you would expect, my need of some time to digest all technicalities that you cared to pass through.
I am delighted with your explanation and thank you very much for that.
Unfortunately i don't seem to able to track its provenance: the seller has bought it in a chandelier factory (scrap lots, left overs, whatever) and that's as back as he will go.
... And no, there is no sign of seams or makers marks in the bottom; completely plain.