Just the three of us for the Middleweights? Anyone else?

Broadsword III needs lengthening to hold the Robots R Us speedos (Mario can look smug at this point and tell me that he told me so last year) so I am thinking about replacing the ply base with some 1/4 steel checkerplate that I found in the street. Broadsword III weighs in at 40 kg but I estimate that that much steel weighs in at around 10 kg. If I have to cut out panels and skin with ali checkerplate then so be it. The benefits of a very sturdy mount for the motors and sword plus protection against whatever the Sandwich attacks with from underneath makes it a good option.