not sure what you mean by key rings, too tough to look up without more info.
but a hand truck I found
it's not pneumatic wheeled though but its item 2611T11 herehttp://www.mcmaster.com/#2611t11/=ba2sqd
this was a tough one I actually did a google search for "NSN hand truck" and got this pagehttp://www.iso-group.com/NSNIndex/19964/19964.aspx
then went down the list picking out descriptions that sounded good.
put the NSNs into webflis public searchhttp://www.dlis.dla.mil/webflis/pub/pub_search.aspx
then clicked on cage codes next to the part numbers till i found a company with a web site.
then copied the part number from webflis, next to their cage code and searched for it on that companies web page.
there goes an hour and a half of my life lol