I am in the process of getting my father's Hamilton Myron brought back to life. I have been, thus far, unable to locate the appropriate crown. It needs to be yellow gold, with out the "H" logo, and have a dust cover. Any suggestions to where I could locate one? I don't have the parts number, so that would be helpful if any one knows it. The size is 5mm. It currently has a 5.5mm, w/o the dust cover, and it leaves an unacceptable gap. Thanks!