[AZKen]

Haven't thought this out that much but the thoughts may spark an idea. Anyway back to the big tractor wheels. The V12 would be the "axle" and possibly you could utilize the tractor brakes to lock the "axle" so as to either just wheel it around the yard in upright position or in lock/brake mode the "axle" would also rotate to reach a certain part of motor when tires rotated...or some manner of locking/unlocking. Bigger the tire, easier the roll. Especially using a "Y" hitch, hitched to a truck or ATV or whatever to pull it around or to rotate for servicing motor.
I have seen jet and propeller aircraft engine stands on military online auctions. Maybe you can find one or at least google them and copy the design.
Google body rotisserie and then hit "images" at top and you will see dozens of ideas. Google VW body rotisserie to see the octagon/multi sided type.