I have one of this type [pic. below], its the same as yours a  3+d  F13 but it must have been made before yours as part of the flag is still visible as a short horizontal line , yours has had more time for the die to clog up and the flag to almost disappear completely . it also has the stick like line running down from Britanniars hand, caused I think by a die clash .  I've seen quite a few of these, and I wouldn't think them to be highly sought after and of any great value.