In this picture are 3 "Diamond K 48" spools which measure 2 5/8" wide X 2 1/8" tall.

They are marked with a Stylized or handwritten "H", the letter "N", and one (far right) with no marking or symbol. The marking on top is where I believe the stencil caught on the flange of the spool. Nothing more.

Again, the questions are;

1) are these insulators and spools found with any other symbols or markings?

2) Is the "Diamond K 48 Made in Occupied Japan" marking found on other style insulators other than the insulators and spools shown here?

3) Has anyone seen another year of manufacture shown, like K 47, or 49 or 50?

Any information or feedback appreciated