yea Ballast.. i have seen.. its so easy to work with paper.. that i have completed three models of jet fighters, in 7 feet in length, all with paper and foam board, fully detailed, including working landing gears, doors, hatches, thrust vectoring nozzles etc.. i will share you if i got permission.. and lots more.. backhoe loaders, excavators.. all working.. adding an example.. now, i works such works, only for Naval institution, as its time consuming and space consuming.. now i little home is almost houseful, with my completed models..
Happy New Year to all my friends with great and safe model making..