to my eye they are Venetian, not the finest quality but possibly 1930s as they have been put on links made of square-section- "rolled gold" (= "gold-filled") wire as shown in a booklet by the boss of the Oxley company, C.J. Oxley who wrote step-by-step instructions "how to make jewellery with wire and beads" and shows exactly how these chains were constructed so a dainty necklace could be made even if you only had a few matching beads with sizeable holes.
i may have mentioned it before-i wrote for our Bead Society of Great Britain newsletter a whole article about Oxley and his wire, exported all over for jewellery making.
i acquired the rights to reprint and sell his booklet, when the company ceased, well over 20+ years ago.
he doesn't discuss beads themselves but it is interesting! email me if anyone is interested to buy a copy... then i will hunt for all the details...