It has been over 18 months since that reel has been used, the line long sold, and the backing transfered to another reel.
I went and checked the reel where the backing now sits- it was 20# cortland dacron (micron) and is around 150 yds. The ID, between the posts, of the reel is 3.600 inches and an outer spool width of 1.5. Due to the raised pillar layout you are able to use the extra space, above and beyond the spool OD (which is exactly 3.262). The Bougle has a fair bit more capacity than an Abel #4 standard arbor, for comparison sakes.
William