You can pint them off yourself: print the pages in landscape mode, on A4 sheets, arranging them properly for printing.
I self-published my own war game rule books by double-sided printing them on paper, at an office supply store. For the covers, I printed these, double-sided, on 110# cardstock, landscape mode,folding these in half, stapling the interior pages within, using a deep-throat stapler. It worked well. I sold more than 150 copies, without any complaints from customers.
My rule books clocked in at 96 pages, as anything beyond that will likely fail because they would be too thick. As I recall my 1977 Traveller books were far less than 96 pages, so this method should work just fine.
Doing it yourself, there are no legal issues that I am aware of. By printing them at an office supply store, you need not worry about maintenance on the printers (double-sided printing causes a lot of wear and tear on the fuser units inside the printers/copiers) -- when one printer/copier has issues, you move to another machine which doesn't have issues… It is far less money to use their printers/copiers, than to own and maintain your own.
POD services usually do not offer stapled, cardstock covers. All of the POD services I've seen only offer perfect bound (pages glued to the spine), as well as hard cover bindings. Check with your POD service to see what the minimum number of pages they accept for perfect bound books. Cheers!