Why not have the set!  Traction, Pits and Slipstream are made from aluminium off cuts from making race car parts, steel and rubber roller bearings with a porcelaine bearings as well as larger ball bearings.   These have come from the gearboxes of the Ford GT and also the Mazda RT24-Ps.  All have been set on a carbon fibre print backgrounds.  The boxes are made from wood and have a glass front.
These make wonderful wall hangings, they can be placed on desks and stand alone on shelving.  They also make great options for corporate gifts and trophies. 
What a great Christmas present for any car or motorsport enthusiast.
 
Each one measures
22.5 x 22.5 and 3cm deep.