Colt Diamondback DOB s/n R449XX

[stonehorses]

Just put a Colt Diamondback .38 in layaway. The serial # is R449XX. Can anyone give me a good estimate when it may have been made? Went to proofhouse.com and the info provided is through 1978...........s/n R13901.
Thanks in advance for any help.

 

[Guillermo]

http://proofhouse.com/colt/index.html

1978 is correct