I’m sorry my bad. The original negative was 1.66 but now the top and bottom has been cropped to fit 16:9.
I have the BATB Laserdisc and it is letterboxed which shows the complete picture.If you take a look at the link below or google BATB laserdisc bluray comparison, You’ll see what I mean.
http://stayornay.com/toons/wp-content/uploads/2015/05/BatB-WIP-Compare-11.jpg
Some prints might be open matte, but it’s definitely a flat 1.85:1 film.