The following two pics are from Saxpics.com
First is a pic of a King Lemaire neck (pics are originally from "Cybersax.com" ). The octave vent appears (to me) to be the same as what is on your King bari. You will also find this configuration on Boosey & Hawkes LaFleur Baris, Amati ABS21, and also a Kohlert design from the 50's(?)
Here's a quote from Cybersax's page (http://cybersax.com/4sale.html
) about the King Lemaire...
This instrument is of a good design derived from the great old Kohlert saxophones. It was built by Amati in Kraslice, The Czech Republic under an arrangement between them, King & SML, where King marketed instruments in North America that were designed & made in Europe by the other two firms. The Kraslice area is in Bohemia, which has changed hands many times over the years as wars raged through Central Europe. Kraslice itself is very near the current German border, and is where Julius Keilwerth and Joseph Kohlert (Amati claims ties to the Kohlert legacy today) built great saxophones & bassoons for many years. The town was called 'Graslitz' at the time Keilwerth started there in 1925. The horn doesn't have a bad pedigree at all, and though it doesn't currently play, the old Kohlert baris that I've played are really rockin' ole dudes.
According to Saxpics, the King/SML association began about 1960(which may help in dating your horn)...
As seen in the second pic below, your horn appears to be a nearly exact copy of the Keilwerth Toneking (I think this pic was originally on "WorldWideSax.com").
For more pics of this Keilwerth go here: