I found someone with a Burton feelgood Smalls 141, but somehow it was shorter than my 139 that i currently have.
This is common. Measure three different 153's and they are likely to all be different lengths. We find that the specs (all of them) that manufacturers put on their sites and in their literature are often way off. Listed lengths are the worst and in some cases are off by as much as 3 cm (up or down from the listed length). That can get pretty significant when two boards that are supposed to be the same size are different from each other by 5 or 6 cm
Could I get you to measure your foot using this method:
Kick your heel (barefoot please, no socks) back against a wall. Mark the floor exactly at the tip of your toe (the one that sticks out furthest - which toe this is will vary by rider). Measure from the mark on the floor to the wall. That is your foot length and is the only measurement that you will want to use. Measure in centimeters if possible, but if not, take inches and multiply by 2.54 (example: an 11.25 inch foot x 2.54 = 28.57 centimeters).