Earl;

My first answer was a bit short and might have been misinterpretable as insulting which I did not intend! It just seems like you were opening up the system and letting it dribble (bleed) into a container...clearly pumping Pedal with a helper is preferable, and your experience with cars certainly exceeds that of most, and bless you for still being active and hands-on!
...of note...sometimes when bleeding a system, it can be difficult to get out a stubborn air bubble trapped in an upper arc in the plumbing or even the rear Brake Valve (located in plumbing on Chassis, just ahead of the Diff, I believe on 444/544s also)...try pumping a bit faster or even raising the tail of vehicle on stands helps dislodge this bubble. Remote Reservoir conversions are available which relocate the Res onto firewall and make it simpler to fill and with greater capacity so more pumps between refills...

Good Hunting!