JPK,

From your post: "By far the most "common" H&H shotgun action I've seen has been the bar action type. The most "common" H&H rifle type I've seen is a back action type."

The following excerpt is from a long description of guns made by Holland and Holland on the Internet Gun Club's fantastic website:

"In 1934 the No. 3 Back-action Hammerless Gun was re-named the "Dominion" (after 1949 it was re-named the "Commonwealth" and continued in production up to the 1960s)."

Note the period that I have posted about, when John Olin owned Winchester. It was not without reason that he did not test a Holland against his model 21 and chose a Purdey instead.

Good hunting!