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I haven't seen anything pre-made but wouldn't this be quite similar to mounting casters like
http://www.ikea.com/us/en/catalog/products/20218526/ http://www.ikea.com/us/en/catalog/products/96671300/
https://www.ebay.com/sch/i.html?_fro...aster&_sacat=0
to a board or even metal grid? Perhaps a few slats which fold cleverly with a piano hinge?
Luggage carts can count as an item. Your lunch bag probably passes as a personal item in addition to carry-on or gets allowed as an extra item like coat, umbrella, CPAP.