I did check the 486th website, Bish. It only mentioned 693, as you say. I was also checking to see if I could find out how many missions "Aries" flew before 6 June. Still looking. The site seems to list missions by crew, rather than by aircraft. Earl McCabe's crew flew "Aries" for six missions before D-Day, so I suppose she should at least carry six of the markers.
Still looking around the net, I found this on ebay:
The nose art looks finished to me, but there are no mission bombs painted on the cockpit armor, visible at the upper right.
In contrast, again, is this photo showing Sgt. Brinkman at work--with the mission bombs clearly visible.
As far as the group "O" goes, I opted to go with the white square, since it obviously appears in photos. Of course, that still means messing with MicroScale's decal potion. So far, the wing insignia went on OK; that only leaves the two on the vertical stabilizers.
Interesting, too, in the above-photo are the long exhaust stains on the port wing, and the shorter ones evident on the starboard wing. Apparently the rubber de-icer boots were left on the vertical stabilizers but removed on the wings and horizontal stabilizer.
I applied the nose art decal today, and K-W's interpretation looks much superior to Academy's (done by Scale-Master, so the sheet says).
Making progress, anyway: built the landing gear, painted the nose and tail turrets and the bomb bay doors, so if nothing goes wrong again I should finish up soon.