Missed countersink - Now what?

So, in a brilliant move seems I missed a countersink on the main spar for the leading edge skin dimple. Last one in the row at the end. Of course I have it all nearly riveted.

So...any suggestions on how I might solve this. I was thinking of flattening the dimple on the leading edge skin, then countersinking the skin for that one in particular. Question is:

1. Do I countersink for a standard AD3 rivet. (the leading edge skin is 0.025")

2. Countersink slightly for NAS1097AD3 rivet and live with a smaller head?,

3. Drill to #30, countersink slightly and use a NAS1097AD4 rivet? (I'm nervous about drilling up a size on the wing spar)

Any other suggestions?

Put your countersink bit on a right angle drill adapte or small right angle drill. Remove just enough rivets to slide the right angle in there and carefully countersink freehand.

Missed hole

Ask Vans to be certain before drilling anything oversize.
I would drill out enough rivets to free the skin enough to get a countersink cutter in on a right angle adapter. Work it by hand to be sure it doesn't go too deep.Just my $.02 opinion.

Hmmm

Ever been working away all day and by the end you just can't see the forest for the trees! I don't know why my head was locked into one solution. I drilled out a few rivets and sure enough I have access to countersink as you suggested. Ahhh my brain hurts.

Thanks guys for the push in the right direction

Nothing like a dramatic story with a happy ending.
Who needs Hollywood when you've got Vansairforce.
Nice work guys. Leaving a countersink out has always been a fear of mine, so it's good to know this potential fix.
Tom.