Nice looking camper, Ed. Loading and unloading the camper does take some getting used to :)
Running a 2x6 along the underside of the wing might not be a bad idea but what's more important is what's in the wings to anchor the bolts into. Could you perhaps see something of the area with one of those inspection cameras at the end of a bendable wand? I'd want to see if the wood at the jacks on the driver's side is still solid and if there is any wood in the corners of the wing on the passenger side where there wasn't a jack before. It sounds like you have a good attitude and will be able to figure it out though :)