Welding that will be tricky, but it can be done. A backing plate will work, but an additional plate on this side, sandwiching the cracked area, will make it more effective. As a short term fix, anyway.
1966 109 5 door wagon 300Tdi "spermaceti fueled"
1994 RRC LeWiB "ruining the air behind me"
All my troubles are Rover