Klaus the Red wrote: And perhaps if she hadn't insisted we spend so much time traipsing around the modern art museums as well, we wouldn't have completely neglected to go to the Musée de l'Armee.

)
Ouch, Klaus, I feel for you, but there is a silver (as in, rather expensive unless you've got plenty sky miles accumulating on your plastic) lining -- later!
While the Middle Ages is only one part of the Musée de l'Armee at the Hôtel des Invalides (any Paris taxi driver can get you there just for the asking, and I've walked the distance between the American USO building in the 8th Arrondissement over the Alexander III bridge to the Hôtel myself), that portion of the museum is a prize collection of remarkably famous stuff. There's a leather covered brigandine there, the so-called Sword of Charlemagne, indeed an excellent cross section of
armes blanches from excavated-condition either Migration- or Viking-era blades on up -- you can get a good feel for the contrast between thirteenth and sixteenth century sword style that could bring a pretty raw beginning student to a middling level of expertise in about one day's examination of the sword collection alone. The armor would take longer, though. At minimum for collecting data from this collection, you need a whole day spent there. Two days would seem luxury unparalleled. They have at least one example of that rather rare style of armor, the smooth Maximilian -- practically no flutes, but all the Maximilian profiles -- armet wide through the visor hinges, globose chest, Maxi taces and tassets, all the bits.
Then there's the rest of the Musée, which leans heavily toward the Napoleonic, and includes one of the biggest collections of circa-1800 artillery tubes I've ever seen. That's not hard, as it's about the only -- still, it fills a plaza on the Invalides grounds.
That silver lining is that now you've got something to go back to Paris for -- heck, so do I. I managed a couple of day-trips to Paris on liberty when I was in the Navy and got to the Invalides each time. Still haven't been up in the Eiffel Tower, either. It's bigger than you'd think...
P.S.: A
Bashford Dean piñata! -- and some of the treats can be little baggies of periodized domehead rivets, flattened down somewhat to that thick panhead shape! And similar baggies of brigandine nails! -- and some cans of Mountain Dew...