All rubber from that era will be dry rotted and the suit is likely falling apart.
Just because something is designed to last a few days in space doesn’t mean it can sit in a shelf for 50 years. Completely different design parameters
I have a German gas mask from WWII that is fully functional in terms of elasticity. The Armstrong suit does not need to be worn again for a trip to the moon. The exterior of the suit is some kind of nylon if IRC. A good deal of the process outlined in the above link is the kind of scientific overkill that is accorded to Egyptian scrolls or Lincoln’s hanky. I could inject an epoxy stabilizer into this suit and it could be displayed for a thousand years. Heck, if Lenin still looks good, this suit - made for harsh environments - isn’t the problem that they want you to pay for.