13" i believe, then plate over the joint for a stronger join.
i`m on with it now... best bet with the wires is a length of welding wire on the end, pull the loom through, the wire wont get wrapped rounfd a cutting disc like string could, and it wont melt as easilt as string when your mating the bits back together. spray some sump oil/wxoyl down the rails while its off.. but leave the back bit til its all welded up (bolt hole/loom hole best bet) or you may find fire inside the leg when welding!
we were going to do just the member, but by the time you`ve got in and got all the welds, then plated up the legs, its easer and less time consuming to do the lot!
..also you cant weld to rust!
good luck!