Just doing mine today - about 10 hours of drilling out rivets. It took a lot longer than I thought. The -3 rivets were easy, but the -4 rivets were really tricky (at least for me). I'm not that good at drilling out rivets, so I did the -3 rivets with a #40 to make sure I didn't touch the original hole - even that was not easy. Surprising how hard it is to keep a drill bit exactly on the middle of a rivet head!
One thing I don't quite understand - even with the cracks, it really looks like the chance of anything failing is close to zero - those HS-710 and HS-714 angles are beefy. I know that there is a good reason for this SB, or it would not exist, just saying that the original design sure looks strong enough.
Couple of business opportunities I saw there:
1) a mini camera that's really tiny and can mount to anything you are working on and give you a super-large macro image of the work - this would have helped me a lot
2) some kind of bushing or guide to keep a drill bit centered on either head of an AN470 rivet.
Update: Yves pointed this tool to me, which I didn't know about! http://www.cleavelandtool.com/Rivet-...ductinfo/RRT4/
I would have paid a lot of money for either of these today! Let's see if I can get the rest done in the next few nights. I'll feel better knowing the SB is applied.