You might want to take a look at the Foredom #18 handpiece. It's
aprox 15 mm in diameter at the widest part & tapers to aprox 7 mm
at the end.. With a handpiece of this diameter you should will be
able to get into the corner.
Thanks Dave! I was able to get it in a bit closer to the angle when I
switched to a #20 handpiece and used a 3-M micro finishing (1200
grit) sanding disc which I bent slightly, followed by hand finishing.
I will definitely check out the #18 handpiece.