thank you for your answer.
i know the Vincent Eras book.
it has got some pictures with keys from 13-16th century
but all the keys are from France, i could not find one from
eastern Europe, and no key which is similar to the key i
have shown.
please see page 35/28, 61/84, 63/88
in Germany we have romanesque (or older) keys with
a similar bow, but bits are different, no breaking throughts,
and they all are hollow.