No sn provided.
H43817 was made in 1947....1943=d thou 1953=n
43-54
Best left to a gunsmith
$60-90, depending on condition.
Depends on what it is choked.
how to remove and replace trigger guard on Harrington Richardson topper shotgun n
you can buy parts for this gun at www.e-gunparts.com
50-100 USD depending on condition.
$100
Less than $100.
$150 in mint condition.