I would say that someone should make a drop-in replacement PCB for the AMIGA mouse.
But there are several problems. One, all of the optical sensors available now (except surplus stock of obsolete parts) output SPI only. They no longer have "quadrature" outputs. Agilent made some early on that did, but aside from buying them a few at a time for exhorbant prices, it's hard to get your hands on any quantity. So this means youd need an additional microcontroller to take the SPI vector data and use that to generate quadrature output pulses for the AMiga.
Two, the lense assembly would have to be custom made to fit the Amiga mouse case. Injection molding is not cheap, and 3d-printing has not reached the level of precision necessary to do an actual lense.
Best idea for you, is to get one of the availble PS/2 or USB to AMIGA mouse adaptors, and find the PC mouse you really like, and use it..
