http://www.diamondgunsmithing.com/page5/page23/index.html
Your serial number indicates that your Ithaca shotgun was made in the year 1920.
It sounds as if you have a Ithaca Crass model shotgun,that was produced in the year 1903 by your serial number.
1924
Impossible to answer without the serial number
What is year of manufacture of a Browning Shotgun A-5 with serial number 01553NP111?
According to the serial number, you have a Crass model gun. The manufacture date is around 1898. Check out www.ithacagunrepair.com.
It was made in 1919.
612
Impossible to answer without the serial number
1905
about 1925
5 years