Those were not rifled as deeply as more modern arms - as they were made directly after the transition from BP to smokeless factory loads in those cartirdges.
The accuracy issues could be from leading, muzzle crown wear/damage, or other issues - like it may not even be sighted-in/zeroed.
The tape residue can be GENTLY removed with hot/soapy water and/or a commercial product named Goo (glue) Be Gone, available at hobby/craft stores.
Untouched/original condition specimens, in the two larger chamberings (.38-40/.38WCF and .44-40/.44WCF) commonly change hands in 85% condition for around $1K-$1500.
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