rc big Scale 1:4 Tiger 1 tank 3mm steel part 1

building a 1:4 scale of the PzKpfw VI, Tiger tank (181)
3 mm steel plate length 1550mm, width 880mm, height + / - 700mm
with a 50cc scooter block, 5 speed gear box,
two hydraulic gear pumps and motors of a ( toro zero turn lawn mower )