Difficulty of bore construction. OR piece isn't logical in context of period. Evaluate the work as a whole. Explains original research or experiment. Explains any deviations or variations from period norm.
Keys are few in number, often covered by fontanelle.
Recorders often have two holes near bell, one stopped with wax. Socket and tenon joints were rare and sealed by wrapped layers of greased fu y thread, not cork. Difficulty of bore construction. OR piece isn't logical in context of period. Special consideration such as personalization to an event, individual or idea.