You can't. But the nice part is that they were all marked from 1934 to 1943. Before 1934, any German paramilitary belt could be used by the SS as long as the belt was black outside. Some were lined with black wool (black to match the color of the uniform) but without anything else linking to an SS use you will never be sure 100%. The picture I am showing now from my former collection (I sold that belt a month ago) is an example: the belt was lined in black wool AND the owner sewn his name, number and unit to it. At that point you are sure it is a SS belt.
After 1943 the Waffen SS was not able to receive almost anything from former RZM suppliers or just about any supplier. Their main way to get what they needed was to get it from wherever possible, whenever possible. Most of surviving sets (both EM and officers) having seen at least some action during the three last year of war are a match of various buckles and leathers. They are ranging from very early SS buckles (before 1934) with very late war leather belts (no leather tongue/holes directly in belt) to any SS buckle with any type of leather belt coming from whatever supply source available by requisition.
Only sets found/liberated in houses or on non fighting units (camp guards, home town security, Kommandantur personal...) will have the chance to be with matching belts and buckle since a belt had, if I recall correctly, a usable service set to 4 years and buckle to 7. So since his belt set would not have been abused or damaged he would have kept it from 1940 to 1945 minimum.
.
.
Bookmarks