OG, these are the tweeters i was referring to. in the Utah coaxial application they had white foam rings surrounding the horn mouth, not unlike the foam rings on JBL LE series tweeters. Radio shack sold these as raw components once upon a time. Internally, these are extremely similar to the made in Japan(foster i think) 2x6 and 4x10 horns that RS sold just a few years later circa mid 70's.

RStweets2

RStweets1

RStweets3

And a "borrowed" pic of a Utah coaxial.

olsonspeaker3