The problem was solved by the above method with a twist when the nut and vice grip started turning while tightening the bolt from above.
I taped the vice grip to the surface using duct tape, went above tightened the bolt, put the next bolt in, taped it, went below, undone the vice grip, threaded the next nut on the next bolt, tightening it by hand, put the grip on the nut, taped it on, went above, tightened the bolt, put the next bolt in, taped it, went below...etc etc etc...

until job finished. Strewth!