If you use thicker aluminium plates, the weight will really reach 1 ton. If thinner plate is used, the weight will surely be lighter and even lighter if you just use plastic materials. This is a rough estimate.
I prefer to alu-plate tank with scaled-thickness (that's the idea of "scaled model tank"). Wether with thin or thick plate, It's heavy anyway.
The real tank has thick armor to amaze me, so should does the scaled model tank.