inherited from my dad. what year was it made, and should i use 32 s & w or 32 s & w long.

I am looking for some clarification about my Colt Official Police .38 Special ctg . Proofhouse.com indicates that my Colt was made in 1961. No Problem. But the Gun Codes and Markings section gave me this for the ctg: ctg WW-II German ordnance code assigned to Karlshutte Waldenburg, Altwasser...