May not be marked, depending on age.
"P" prefix indicates 1953
Harrington & Richardson used the Prefix AT in 1983.
How old is my Topper 88 HARRINGTON AND RICHARDSON GUN serial number
Harrington & Richardson did not make a Model 1900. Hopkins and Allen did.
1971
1980
Serail number and features
No way to answer without the serial number.
50-250 usd
The Harrington & Richardson Model 088, with the serial number AZ438056, was likely produced in the early 1980s. Harrington & Richardson used a specific serial number system, and the "AZ" prefix indicates that it was manufactured during that time period. For exact dating, further details or manufacturer records would be needed, as production timelines can vary.
I purchased a new Harrington & Richardson 12 gauge model 088 from K-Mart in 1980.
Your harrington and richardson model 900 was made between the years 1962-1973.