The fill level is to the neck--very little to the Angel's share. I also received a nicely detailed analysis from one Craig Harvey of DIAGEO, who also placed it between 1947-1951. (Unfortunately, he wouldn't give an estimate--pointed me to a fellow at McTear's who could value it--for a fee--and provide advice.)
The labels are actually in good shape; only the Illinois tax stamp and the neck label show any appreciable wear, and some damage to the lead cap--it looks like someone, at some long remove in the past, started to pull the string to open it and thought better before fully cutting through the lead.
I'm in a bit of a quandary. If it were clearly an inexpensive bottle, I'd just drink it. If it were clearly valuable, I'd have to find out how to market it. This seems to be all over the place in auctions, at least from McTear's (
http://www.mctears.co.uk) past auctions.
Oh my ducats, oh my daughter...