I'd be interested in knowing what the dealer(s) said about them. Really, any information you have would be useful.

Essentially, all these pieces could possibly be from Vietnam.

The stone slit rings are Dong Son, I think - similar to the one I posted earlier. The glass slit rings are from the Sa Huynh culture further south in Vietnam - about 2,000 years old. The squarish little slit ring is from the Dong Dau culture that bridged the gap between Phung Nguyen and Dong Son (1500BCE-700 or thereabouts). It's very pretty and quite rare. I'll attach a page from a Vietnamese archaeology journal where you can just about see a similar one at #4. With the spiked protuberances, it's a design that evolved through different cultures, culminating in Sa Huynh ear ornaments like the one attached.

I don't remember having seen a long flat rectangular bead like the one you picture; it doesn't look Tircul (Pyu) to me but I could easily be wrong.

The tubular beads could be from Phung Nguyen, but they look a little less well rounded than I would expect from there and I think they're probably later. Very similar beads were manufactured over a period of nearly 1,500 years not only in Vietnam and possibly Thailand, but also in western China (as Red Mountain showed us) and in the Philippines and Taiwan. In the first millennium BCE, as nephrite deposits in Vietnam started to run out a remarkable long-distance maritime trade began to develop between Vietnam, Taiwan and the Philippines that saw the exchange not only of raw Taiwanese jade but also of finished and partially finished artefacts.

There are also recent fakes of these tubular beads so one has to be careful; it's a good sign if they still retain their patina.

I hope this helps to fill in some of the gaps.

Best,

Will