Stu,
This is all very interesting. Thanks for all those pictures and great info,...
What vastly differentiates the 1970's LA Camco Keller shells from all the others are the edges.
During those last years, Camco did a unique sharp rounded cut from both sides. On the first picture you can see how they look from a side-angle. It would be interesting to get a close up of the edge from your kit.
About the shell-thicknesses and diameters, I tried to do some accurate measurements a while ago and compared the 1960's Jasper shells to the later Keller shells from the 1970's.
The measurements in thickness from the 6-ply Jasper shells varied between 0,201 and 0,208 inch. The 6-ply Keller shells readings gave a number between 0,199 and 0,206 inch.
To measure the diameters, I put the shells on a flat table top, used a measuring triangle and placed it as accurate as I could on the opposite sides of each shell.
The outer diameter from both the 13” shells are exactly the same and measure 12,83 inch.
The 16” Jasper shell measures 15,89 inch and the 16” LA Keller shell is 15,87 inch.
In other words, the Camco shells are identical even though they came from a different manufacturer and another era.
The general misconception that the LA Keller shells are extra-undersized comes from the fact that the top of the edges are leaning inward. This allows the heads to float freely on the top-edge and guarantee most-optimal contact with any drum-head you would choose. This explains LA Camco's legendary ease of tuning, versatility and unmatched resonance. Notice the big gap between the drum-head rim and the outer edge of the shell on the second picture.
