Ken,
Seems a little odd that your distributor is supplying 10 degrees under 850 rpm, and yet doesn't reach max until 3000 rpm.
I'd say either a spring is missing/not fitted, or one is broken.
It may have given the result the previous owner wanted, and if you are happy with how it is, that's all that matters.
So in the end, you have 10 BTDC cranking, 20BTDC at idle and 34BTDC at 3000 rpm. If the timing is steady, you have the best of all worlds, low timing to allow easy hot starts, and enough for a quality idle.
http://i155.photobucket.com/albums/s...llory-2010.jpg