The answer to the pickup materials is answered later. The back bracket is pot metal. The pickup back piece is, but somehow always survives. Pickup head covers are always copper or brass. They always hold up well.
As far as the dynamic speaker goes, once they converted to it, they never would have gone back to the magnetic Loudspeaker 100. It would have been like going back to acoustical racording after the change. As far as the break poinbt from magnetic to dynamic, there was one serial num,ber with the LS100 speaker, and the next one had the LS104. We'd have to know who had those two sets, and I'm afraid that it will never happen. The Hyperion is a fairly scarce set. I can supply a pix of the Brunswick P-11 and a 3NW8 that I have. They're handsome sets. Remember that Brunswick was a furniture manufacturer, so their cabinets are beautiful in their own styles. And, since Victor made their own furniture, they too, are beautiful in design and have survived the years miraculously. I have a Victor 9-18 that has the most perfect cabinet possible, and it was made in late 1928. There are quite a few excellent examples that collectors have. That's the reason that people like us revere these and other masterpieces from history.
