At some point in the mid 2000's Shopsmith introduced a line of steel storage cabinets (or toolboxes) that could be used in several different configurations, but most conveniently they would fit under a Mark V and were able to roll on included casters. Below is a screen capture from Shopsmith.com in 2008. These cabinets have long since been discontinued and are shown here for historical purposes and to aid folks in buying or selling on the used market.
Steel Storage Cabinets roll snugly under your MARK V to hold your Shopsmith Accessories
Designed specifically to work with your MARK V and help you gain control over workshop clutter. Choose from three 16" w X 14" d (front-to-back), 20-gauge steel Cabinets that you can use individually, connect together side-by-side (they fit perfectly between the legs of your MARK V) or stack.
Sturdy drawers support up to 60 lbs each and open on ball bearing glides that feature a gentle locking detent to alert you when closed.
The full width drawer handles are flush with the Cabinet front when closed and hold write-on label strips, with see-through covers.
Each Cabinet comes with four 2" diameter rubber-tired, ball bearing swivel casters...two of which lock with a quick step of the toe.
Outside Cabinet Dimensions: 16" w X 14" d X 17-1/4" h (+ 2-5/8" h Casters).
Inside Drawer Dimensions: 12-14" w X 12-1/2" d (Drawer heights vary)
Connect all three together horizontally with drop-in L-Pins (included) or use the caster mounting hardware to bolt them together vertically. Each Cabinet also includes two steel Handles plus all required hardware.
*Heights are to top of Drawer front. Drawers will close if stored items protrude slightly higher than Drawer front.