I have been toying with the idea of making up a German style high seat but built in the drywall lining steel galvanised sections bolted together at the joints with rubber insulating pads (scrap truck inner tubes) add wooden posts to the sections at the bottom to sit on ground plates/slabs. All the stresses are going in a straight down direction anyway so it should not buckle unless your name is Cracker of tv fame.
I did the CAD on Catia v4 and it weighs out at 17kg. Just right for adding the wheels as on the other post here yesterday for moving about as a 1 man job to where the roe boar etc are. Plus it will not rust and should weather like an old garage door in time.
Have not found the time to build it yet.