Best way to use reclaimed plywood

[venkatbo]

I managed to salvage nine 2' x 3' (54 sqft total) 3-ply maple cutouts. What base material would you recommend that I glue/nail it to, so I can make the base-box for my workbench - much like what Steve has built:

http://www.bt3central.com/showthread.php?t=19422
(btw, Thanks Steve)

Thanks,
/venkat