"working man" = Salt of the earth. Def./People who are salt of the earth are decent, dependable and unpretentious.

...to quote dubbletrubble. I might also add the term "working man" was associated with anyone who labored with his hands. For further clarification listen to a few Meryl Haggard tunes. My grandfather's guns were a M-73 Winchester and some unknown variety of SxS. I have the '73 and wish I had the double.