To me it seems it is not Ioannis but IOHANNIS or even JOHANNIS.
May it be it refers to refer to Johannis Brach?!
There might be other candidates as well, like Johannis Hoppe, Johannes Mumm, Johannes Wundes and maybe others I do not know. The punch mark should give more information.
The "anchor" mark is most likely a talismanic symbol found on many swords, and I do not think it can be useful for identifying the maker.
Anyhow, magnificent rapier!
