I didn't mean to sound like it was impossible, Mike, just for a first project, to hit size, parallelism, and squareness is going to be quite the challenge. And without knowing what instruments are available to verify each phase in the process.......difficult may be a little bit understated.
Plus, comparing a grinder with scraping, I dunno. Scraping is at best a series of high spots. Granted, they can be very close together, but I don't think you could scrape to a 4µ finish, but you surely can grind one. And those high points are much, much closer than you can ever get hand scraping. And then there is lapping, beyond grinding. I know there is a lot of deserved respect for the art of scraping, but there is a reason there is so much more grinding and lapping in the modern world. For the sake of nostalgia, or originality, or even just because a person doesn't own or have access to grinding and lapping machinery, scraping is a very viable option. But I'll never be convinced it is equal to or superior to grinding.