Should vs. shall?

Hi again, I’d like to understand the difference between shall and should in this sentence:

Where shall I put these files?
Where should I put these files?

Is there any difference and if so, when shall/should I use which? Thanks!

As I understand it, in these questions, if you use shall, you are offering to put the files away and showing more willingness to help. It sounds more like: Where can I put them? The use of should here implies obligation or duty. This question sounds more like: Where do I have to put them?

It would be nice to have other opinions on this, though, as the rules are a bit complicated.

To me they have nearly the same meaning, the difference being one of softness or politeness, rather than of meaning. For me the difference is more in the realm of that between, “Can I do this?” and “Could I do this?”

Maybe I’m not qualified to comment on this, though, because the word “shall” is almost never used in America, and 99.9% of the time we would ask this question using “should”.

Now we need Alan’s opinion.