Thank you, Mr. Harris, for your feedback. Having started this hobby almost
40 years ago when there was no literature or MMD, it took me years to get as
far as I have; don't be embarrassed about the long learning curve. Threads
like this in MMD will surely make this easier for new people in this era.

I have never seen a Standard action with sealed pouches; the few that I have
redone worked OK without sealing. I would proceed with caution, especially
since you have 86 notes that do work correctly.

Sealing the main pouches would seem to be unnecessary on any double-valve
action. The primary acts as a switch, admitting either pure vacuum or pure
atmosphere to the main pouch thru a comparatively large passage. Since there
is no bleed in the secondary pneumatic circuit, there would have to be a
huge amount of seepage thru the main pouch to defeat the effect of
atmospheric pressure thru the primary, if it is fully opened to the
atmosphere. If 2 individual main pouches are that porous, replace them,
rather than having to go thru the whole process of readjusting the valve
stem length or other main chest work that sealing all the main pouches
night involve.