blindluck... I'll give it a go. In the nuances of measuring North American game animals, the palm length measurement of a moose is perhaps the most subjective of them all. Many drawn out discussions have resulted at various shows, especially when measuring some big bulls that come out of Alaska that have folds in their palms.
You are correct in that every point, including those on the brows, are counted as one inch regardless if it is 1 inch or 10 inches. Remember a "bump" does not qualify, as a point is considered to be longer than it is wide at least one inch down from the top of the point. I use a 1" diameter piece of copper pipe cut to a 1" length. Slip it on what you hope is a point and if the tip of the point protrudes... you got a winner.
Things to consider when measuring the length:
1. Measure across the back side of the palm.
2. The line you establish to measure is the one most parallel to the inside of the palm. This is where opinions can vary.
3. The starting point at the top of the palm is in the swale between any two points or bumps. They do not have to be scoreable points.
4. If the brow is split, starting at any of the crotches on the brow establish the line to one of the top crotches that is most parallel and also give the greatest length measurement.
5. If the brow is a single point, the same line needs to be established using any place on the brow tine that gives you the most parallel and greatest measurement. That starting point on the brow tine is generally about half way down it just as it begins to sweep back up.
I use a piece of freezer tape to establish the length line. You can pick it up and lay it back down easily as it usually takes a few goes. Another eye is always welcome, especially when working on a potential book animal.
Hope this helps a bit... good luck.