Glad your tackling it first. I am going to do it on my bobber as well but haven't got that far. I bet wiring will be easy. Bracket will probably be hardest part. You might be able to find a used bracket off newer bike and modify? Have you looked on ebay for speedo?
Not in a day or two. I've found them before. Didn't know if anybody else had tried it lol. Was hoping it would be a "oh yeah you can just swap this and be done" but... Hell it's more fun this way. I'm still trying to get an idea of what I want to do with it after I figure out how to move it. I have a few other mods in mind to so.