Torque Boxes - do it yourself or not?

Hello again guys and gals,

Just wanted to get some input on torque boxes.

My 69 cougar convertible needs new ones, and badly. this is the first thing I want to do to her this summer but wanted to see if anyone on here had either A) done torque boxes themselves or B) knew someone who did.

I have a friend that is very good at welding who offered to help me on this but I'm a bit hesitant. From what I can tell the procedure is pretty extensive and I know the torque boxes are extremely important to the stability of the car.

Any input would be appreciated.

Thank you!