I am looking for information regarding these Made in Occupied Japan insulators, and the spools in the next picture. I refer to these insulators as the Diamond "K" 48 Occupied Japans. These are 2 3/8" X 3 5/8" tall, and the larger size is 2 3/8" X 5 1/8" tall. The only major difference in any of these insulators is the small symbol found below the "Made in Occupied Japan" circle. As you can see here, left to right, an "M", similar to the McDonalds Golden Arches, the letter "N", the number "8" and another "N". These are also found with a stylized or handwritten letter "H". I also have a spool with no symbol or other marking

My questions are; besides these 2 sizes of insulators, and the spools shown in the next pictures,

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