Installing the tailwheel mount on your back, from the bottom side of the fuselage is no fun. At least, it's less fun than doing when the fuselage was inverted a few months ago.
I had removed the tailwheel mount a few months ago to make the fitting of the vertical stab easier. It was not time to re-install it. Not much room to get fingers in there, let alone wrenches. Used needle-nose pliers to get the washers onto the bolts, then had to tape the nuts into a box wrench to get them started. Not bad, just time consuming with wierd contortions to get my arm positioned just right.
Tailwheel Mount Installed (ran out of AN3-7A on bottom)