AFAIK, the barrels and receiver covers on both the H001 levergun H003 pumpgun are identical.
Your gun "might" have had an H001 barrel installed at assembly because a properly-stamped barrel wasn't available (or stamping not checked).
If it works OK, I wouldn't fret - if you have any mechanical/accuracy issues, zip an email out to Mr. Imperato (Henry Prexy).
info@henryrepeating.com
He usually takes care of ALL Henry customers, tuit' suite.
Be sure to mention your firing pin issue - he most likely will want to know or take action on that.
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