Prior to the issuance of official SDPD ID Cards, employees were assigned duty badges. 
Some of the more unique badges can be found below. These badges average more than 70-years-old and are depicted in "as in condition."
Circa 1940's
Hallmark Entemann Rovin
This badge is 3/4 scale of a duty badge. Not much is known about why these were issued. Perhaps they were pocket badges.
1932 - 1933

Mayor John  F. Forward Jr. badge. Why the breast badge is labeled "California" and not "Police" is not known.

1932 - 1933

Mayor John  F. Forward Jr. breast badge. 

1971

Mayor Pete Wilson wallet badge. 
1940's

The double bars in the number panel make this an exceptionally unique badge.

Early 1930's CITY BUDGET OFFICER

Issued to John Colguhoun upon his 1936 appointment to office. Like mayors and council members, the city budget officer is not a member of the SDPD however they are issued San Diego Police badges.