I guess if it says linistepper on the PCB, then anyone who knows how to use google will find piclist.com, but if you have the chance.. it would be nice.
Can you email all the files to me (jamesnewton al piclist d0t c0rm) or ftp them to
ftp://ftp.piclist.com/in including the videos, board files, photos, etc? I'll put them up on the site and make them available for download.
Do you have plans to publish the plans for the mill? What sort of repeatibility and accuracy are you getting?
The chopper version would require more of a design change than just the drivers. The method of sensing and regulating the current would be very different. Best to design a different controller, and there are others around that do that sort of thing.