Harrington and Richardson used serial numbers that started with AM in 1974. The company had similar shotguns being built from 1974 to 1981.
How old is my Topper 88 HARRINGTON AND RICHARDSON GUN serial number
Harrington & Richardson used the Prefix AT in 1983.
1980
$100
how to remove and replace trigger guard on Harrington Richardson topper shotgun n
Less than $100.
Typically a used topper will run between $50 and $150 depending on condition.
Late 60's to mid 90's
About $75-$125, depending on condition.
100 USD or so
Since it has a serial number, it was made after 1968. They were made at least through the 1990's, but I know of no source of serial number dating info for recent H&R guns. * Harrington & Richardson manufactured the shotgun in 1974.
50-150 USD or so