got any 1/2" or 3/4" plywood ?
cut you the size that suits you and what you want to display........
get yourself some wood trim molding.........take your pick, especially if you're near Lowe's or Home Depot (Go Tony)..............'
attach the molding along the base of desired plywood thickness and determinate size flush along the bottom of the wood piece...........
now's the tough part........where i was in Dallas there was a company that made custom acrylic / lexan tops to go on my homemade bases.........
company was called Contemporary Designs in Grand Praire.............
gave 'em the 3 ID dimensions and in less than 10 working days i had a display case.........the base of which you can make into what ever melts your butter.........a dio..........tarmac..............field........etc....etc........
hope this helps and i do realize you might not be near any where that makes acrylic or lexan tops to fit your ID's...........but, maybe this'll give ya head start on something that DOES suit ya...........
best 'o luck Aviator...........