Junkerman-occupation not name

I am familiar with the word "Junker" but I am more curious about the word "junkerman" as an occupation. I am assuming that it is a worker for a junker. Like a serf. Has anyone else come across the term "junkerman" in their research or know what it means?

As a matter of fact, "junkerman" seems to be a very unusual term. If it is
correctly copied, it is NOT German (as a German word for an occupation, the
term would have to be capitalized and written with double 'n' at the end).
Depending on the context in which it appears, the word could be a corruption
of the English/American "junkman". The latter is either "a dealer in
resalable used metal, paper, rags, and other junk" (American, dating back to
1870-75) or "a member of a crew of a junk [= a Chinese sailing vessel]"
(coined 1860-65). This is what the 'Random House Unabridged Dictionary', 2nd
ed., of 1993 offers as explanations.
If "junkerman" were a more or less spontaneous creation of an American
clerk and actually referred to a person that used to work for a "Junker", it
would probably refer to a farm-laborer or a footman in a "Junker"'s
houshold, by no means "a serf".

Rolf-Peter