In the late 90s I discovered the Major General's Ourgistan site.
The noted explorer/adventurer, Sir Randall, has created an area of mystery and intrigue we call Randistan, the portal to which is an unassuming basement in Lincoln, NE.

Our little tip o' the hat.
...This landship is built on a chasis of a tracked vehicle found in a thrift store bin. The upper cabin is a plastic coffin.
Looks a bit like the GI Joe Cobra I.M.P, suggested by the good Major General, though never completed on the site. Personally, I want to try and use with 15mm as a proper Leviathan of the Land.
Did you have to chop the top of the track units to put the balconies on? If so, I've an IMP with chopped tracks waiting something similar.

The coffin, by the way, purely imspired!
Doug