The first question is about the clothing of an American soldier in Japan. Worded as such, it doesn't seem interesting to me. A more historical question would include a guess: Is this during or after World War II/Korean War/Vietnam war, etc.? The followup would be: "Why would a "GI" be issued this, and not that?"
The gist of the second question was something like, I'm used to five digit zip codes and this letter/photograph has a two digit code. At what time point did zip codes change from two to five digits (so that the OP can narrow down the time frame for this photo)? And the logical followup question would be, "why did this change in zip codes occur? It is the last question that would make the post historically interesting.
As "standalone" questions, I feel that they can fall into the realm of "archaeology,: "trivia" or "curiosity," unless an active attempt is made to involve history in some way. This can be achieved by putting in appropriate "hooks" into the question to link it to historical events. Should we require such "hooks" before allowing such questions?
Put another way, should we encourage people that want IDs to ask for historical context (as I did by coaching my answer in that vein)? Or should we just take and answer the questions at "face value," even though there is, or could be, quite a bit of history behind the "face?"