Thanks all! I'm not a builder so I don't have much experience with RICE and all that, but I got this figured out by looking at the config on one NP saber, measuring out the blade it came with, measuring the difference between that blade and the new one, and using jbkuma's reference to calculate the difference in pixels. Don't know if I got the number exactly right, but I set it for 131 and everything looks good.
Kind of proud of myself for that bit of problem solving :)