Leveling a QB fus for gear install

Full disclosure.
This should have been the very first thing I did when I received my QB fus but I got caught in the Grove gear fiasco and didn't have them at the time so I moved on.
Fast forward to today where I rolled the fus inverted to begin the gear install process. The instructions say to level via the F-822-1. On a QB this is not accessible from the outside. Am I meant be crawling under the fus and placing a level up on the cockpit floor or have people had success leveling elsewhere? I was thinking since I have the tail surfaces back off I could level at the F-819 aft deck where I leveled the fus for the tail group install.
Where did you measure for level when installing your gear?
I am thinking between the two directions the lateral level is more important than the longitudinal level.

If you installed Grove gear then any helpful advice would be appreciated.
I already see I am going to be required to relieve the skin a bit to get the outer saddles in.
I was also looking at the Vans out wear plates and the #40 access holes pre-punched in the skin. Is it just me or do they not quite line up?

As always, thanks in advance for your input.

Sam, see my log for August 2012. As I recall, I placed a level on the bottom of the fuse over the main spar area. I checked a couple of locations both fore and aft of that point and both were level, so I went with that. I did cut away some of the skin to allow room for the larger grove outer brackets. I'm not sure which #40 holes you are referring to, but there are 2 holes that need to be drilled up to #19, machine c/s and screws installed. This is mentioned in the construction manual previous to where the instructions say to begin for a QB kit. Good luck with your build!