It's suppose to be "BIG". Whether it a cutting error or just clogged mold I don't know, the camera shot is of the "I". A loop with the bottle in hand would say for sure.
Here's another acl Big Bot'l from gono.com - but it's different than the one that has the little guy on it. Scroll to the bottom of the page - image is in the J position - 1946 - No city/state/bottler http://www.gono.com/museum2003/paintedlbottles/paintedb2.htm
Chris Weide list a Big Bot-L acl that is identical to the one I just posted and shows a good picture of it. The listing is slightly out of alphabetical order and is the last of the ones that start with "Big." It is listed as being from Las Cruses, New Mexico - 1940 Coca Cola Bottling Company ( I am not posting a picture of the bottle because the images are copyrighted ) Click on the green number to see the bottle http://ca-yd.com/textfile/bottles/ACLWEB_B.HTM
P.S. The description with the Collectors Weekly mystery bottle says the bottle has "Registered" embossed on it. This indicates that either the bottle style itself or else the term "Bot'L" was Trademarked at some point. I have just begun a Trademark search for it but so far have not found anything.