Cyclecommute,
Those numbers look plausible. In my crude static test with a 26 lbs bike-no suspension- the front was about 12 lbs the rear about 14 lbs.

Jamming-locking- on the front brake and giving the seat tube a push the front would jump to 17-18 lbs before it lost traction . I couldn't measure the rear weight simultaneously because I had just one scale. I could "feel" the rear starting to lift/lighten.

Jamming-locking-the rear- with the rear on the scale-the 14 lbs rear would drop to 10 lbs or so, and then lose traction.

I did the same thing with a suspended bike-no rider-and got the same result. There would be any real for dive or rear extension since it wasn't loaded-no rider.

My guess is in actual riding-with true front tire compression or with fork compression-you would actually get a number=weight- greater than the total weight for just an instant as the front actually accelerated downward toward the contact patch as the suspension "worked" .A 200 lb bike rider could actually give an instantaneous reading of over 200 lbs if your tire compressed or the suspension compressed.Of course this assumes good enough traction to really slow the wheel/tire without skidding.

Oh well, interesting discussion.
Charlie

PS This has been a "full contact" discussion!!
PPS Bottom line is your front brake does most of the braking-well accepted in motorcycle circles for the last 30 years despite some holdover of "your front brake is dangerous" bs.Of course the engineers and racers knew this from the beginning of time.