A little rough is historically accurate. . .
I agree with Kurt about how difficult it might be to get it absolutely smooth. That said, take a look at some of the old pix of those "dustbin" racing fairings of yore -- obviously one-off, and YES! obviously done by human hands! (Sadly, some dustbin fairings were prone to causing the bike to take to the dirt in sidewinds, but not because they were handmade.)
Watch out for cookie crumbs in the tank --
Brother, you've got a "set" to take this project on, and GOOD ON YOU!
FYI, the excellent book, [I]Shopcraft as Soulcraft [/I]addresses the current lack of shop classes in schools. When I grew up in Arkansas (one of the poorest states) during the 60's, our high school had BIG woodworking and metal shops with plenty of machine tools to play with. Wonder how many guys got a CAREER out of what they learned in shop class? Lots, is my guess.