If you had a more capable welder, I would recommend you get a carbon arc gouging lead and a box of rods to bevel out the cracks. If your time is worth much, that would be the way to go. As far as going vertical with 7018, if you had a friend to guide a little, that would be a good place to get comfortable with it. Once you get the first few passes in and you able to have enough room to weave a little you should pick up the uphill pretty quickly.
That was some 1/2” I cut out on Thursday in the frame of dirt bucket. That took all of about 6 minutes once the leads were pulled out.
It would be very interesting to see some larger pictures of the cracked area. It was a little hard to follow exactly how they were oriented.
The guys around here that move portable sheds and outbuilding use trucks and hydraulic trailers. They do not have near as much style as your operation there! Bravo!