martin08,

Once again, Thanks for your information. The ColtForum topic was a wealth of information. I have narrowed the date down to 2nd Qtr. 1918, probably early May.
My aim was to try and provide as much information as I could when I post the pistol for sale. Between arthritic thumbs and a robust hammer spring, I cannot cock the hammer single handed.
Time to begin thinning the herd anyway and let someone else enjoy this one.

Regards,
GS38

P.S. Your October 1918 is absolutely gorgeous! Congratulation on acquiring that one. My S&W M1917 is similar. Except it isn't a Colt....