Well, as you have access to overhead gantry and forklift it would be easy to just turn it over for welding both sides. Stainless steel and torches don't go that well together so I would opt out of that one. You can certainly fill some wide gaps with mig and if you have some brass plate 50mm wide or so you can just weld over that and then take it away for some of the other areas that are too small for a fill but too big for straight welding. if you held some pieces of plate behind and had someone mark it with chalk you can then cut some rough fillers with the gas axe and fit and weld them in place. Just by the look at the photo's of what I can see I would estimate 2 days and it would be as good as new.
Colin.
