That would depend on whether the stamp is a work of authorship within the subject matter of copyright as set forth in
section 102 of the Copyright Act.
IF the stamp is a work of authorship, your removal of the existing stamp would destroy the copy. No problem with that. However, at that point you're essentially starting from scratch. There's no meaningful difference between the piece of wood (I assume) that used to have the stamp and a random, similarly shaped piece of wood that never had a stamp.
I don't know that there's any priority here, but I agree that it's another issue that needs to be considered. If the OP legally owns a "whiskey barrel head" that happens to have a trademark on it, there's no issue with selling that item. However, the removal of the existing stamp and application of a new stamp raises both copyright and trademark issues. I also agree that a consultation with an IP attorney is needed.