The Collaborative International Dictionary of English v.0.48:

Proface \Pro"face\, interj. [OF. prou face, prou fasse; prou
   profit + faire to make, do.]
   Much good may it do you! -- a familiar salutation or welcome.
   [Obs.]
   [1913 Webster]

         Master page, good master page, sit. Proface! --Shak.
   [1913 Webster]