Some types of information can be replicated, even when the original documentation is lost. Given the German penchant for industry-wide standardized codes and near-universal marking of items, it's rather easy to replicate the missing chunks. They were a nation, after all, which kept METICULOUS records on mass atrocities, even when it was clearly apparant that they had lost the war, and such records would be of obvious value to the occupying powers in convening atrocity trials. (And lest one forget, while the atrocities committed against German citizens could be rationalized away by a lawyer as am "internal matter" outside the jurisdiction of the Allies, the atrocities committed against foreign nationals from conquered territories were already well-established as war crimes.)
Other types of information CANNOT be reconstructed -- once they are gone, they are lost forever.
If no one bothers to write down the non-functional difference between two shovels, and there is no period photography (or other "reliable" imagery) you'll NEVER be able to positively identify the context of the differences -- there just isn't enough signal in the noise. Without starting a food fight here, eyewitness testimony to events of 60 years ago of an almost insignificant (to the witnesses at the time) obscurity is not reliable at all.
Of the vets (any service, any period) here, how many of you have caught YOURSELF realizing you've misremembered relatively unimportant details -- such as realizing you can't POSSIBLY have been using a particular piece of kit or weapon AS YOU WERE "SURE" YOU USED on a particular mission, becuase it wasn't even on issue yet? (Or you come across an old photo that establishes the error?) If you used both pieces of equipment (or even a merely similar one), it's easy to confuse the two -- especially when the difference was irrelevant to you at the time. And, over time, the "margin for error" of memory becomes quite significant, so that even somewhat significant details of key equipment become mistaken.
I'll give you a BLATANT example of the problems of unsupported memory, from less than 40 years ago (and less than 25 when I ran into it). . . Vietnam vet (one tour) of an armor unit; served in the same tank his whole tour. He stayed in and served until about 1990. He was telling me about his "M60" tank in Vietnam, and then proudly showed me a picture of "his" tank that was clearly an M48 (complete to 90mm gun). (And I later found out there was a conscious decision by the US not to even send any M60s to Vietnam -- they weren't needed and there was no point in letting the top of the line MBT risk being captured and shipped to the USSR.) After I asked him why the main gun looked so different (aside from the main gun, an M48 and an M60 look quite similar -- and the final, 1970's M48A5 variant was effectively an M48 upgraded to M60 standard), he realized that he HAD served on an M48 in Vietnam; it's just that ALL of his tank time for the next 20 years had been in M60's, and his brain "superimposed" his "M60" template on to his "M48" memories.
That's a Main Battle Tank the guy served on in combat, which comprised his primary weapon, his protection, and his fellow crewmates. It had a NAME, and saved his ass in combat by DIRECTLY stopping bullets. Not a shovel. . .
My first entrenching tool after Basic was an old wood handled one with the folding pick and a canvas carrier. At some point before I graduated Drill Sergeant School, I was issued the new style with the triangular handle that folded to no bigger than the spade, no pick, and a rubber carrier. I couldn't tell you WHEN I switched e-tools, even though I preferred the older one (MUCH better tool) and bitched loudly and longly that I had to turn it in, after managing to hang on to it so long. That's in less than 20 years, and the changeover was so significant to me I CLEARLY remember it -- but I couldn't tell you any details that would let me date it any closer. Same thing for the changeover from steel pot to kevlar, rubber OD poncho for nylon woodland style, or when the First Sergeant ordered me to take my M1956 canvas buttpack off and use a current nylon one. Again, I remember each of these changeovers clearly -- but couldn't date them outside a very vague range.