The date of manufacture of Colt 1903 Hammerless .32 is 1916.(193000-234999)
about 1925
You can find out at Proofhouse.com in the Colt tables.
1917
about 1909
about 1908
1908,
1920
Found a Colt 1903 hammerless with that serial number made in 1917.
The 1903 Colt Hammerless .32 with serial # 137295 was manufactured in 1912. about 1913
Your 1903 colt hammerless 32. was made by colt in 1920.
1934 for the Colt 1903 hammerless .32.