Steve is pretty accurate on his dating. To back him up, take a look at the 1954 catalog at LH

Page 13, two piece horn.
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Back cover, old one piece.

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I had a couple pairs one not sure of date and one pair 1952. There was an overlap where both horns were available.

From what I understand the one piece resulted in a lot of rejects. It was a complicated multi-piece mold and if parts of the mold shifted the horn was ruined. The two piece used cheaper tooling and created less scrap.

FWIW the 802 originally used the same 3 bolt mount as JBL one inchers later used. When the horns, specifically the 808, went to 2 piece castings, it was changed to 2 bolt.

Here's an 801B (field core 802) see top image

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