I did the burnishing procedure and the brakes are working much better. I can now lock up the front axle in gravel even after reducing the gain to 7.5 from 10. I did check the drum temperature after doing the burnishing procedure and it read about 310F so they still got fairly warm even with only moderate braking and allowing two or three miles of slow driving between between applications. I did try to keep the gain down to 4.0 during the burnishing. This temperature is right on what the Dexter guy told me so it seems to work. The brakes had to cool down for the improvement to be really noticeable. Unfortunately, by the time they were cool it had started raining so I don't have dry pavement results yet but hope to get that tomorrow.
My only concerns now are the nature of linked axles to skid the front axle and the possibility of fading if 300F causes fade. I least I got to a point where I feel that I can drive reasonably safely under normal conditions. If I ever get $600 to blow I may try to upgrade the rear axle from 12" X 2" brakes to 12 1/4" X 3 3/8". Thay might solve both of my remaining concerns.
Thanks for the good info.