[Dto7]

from looking at Spalding guides

1906 Portsmouth, Va.--just a P on the uniform
1908 Portsmouth, Va.--P on uniform
1920 Portsmouth, Va--no lettering
1921 Portsmouth, Va--Truckers across uniform

1908 Portsmouth, Ohio--had jackets on
1910 Portsmouth, Ohio--nothing on front of uniform
1911 Portsmouth, Ohio---P on uniform
1912 Portsmouth, Ohio--P on uniform
1915 Portsmouth, Ohio--in street clothes

no other pictures of the teams in the guides to 1930.

If you go to Google Books Search and type in Portsmouth baseball, there's a book about the Va. team and photos you can look at. nothing that looks like your uniform..