I didn't use any planes on mine.
I don't have a bandsaw, so there were no bandsaw marks. I cut the barrel inlet and ramrod groove with chisels and scrapers. Roughed the blank down with a handsaw chisels and rasps.
I think the planes would be helpful if you are building more than one gun, or if you just happen to have them, but they're probably overkill for a single gun. You can get the same results (with a little more work) without them.
I found that making scrapers that were just undersized copies of the barrel worked especially well for cleaning up after the bulk of the wood was removed. And a drill bit the same size as the ramrod with a flat ground end, works as a scraper for the ramrod groove.
Now, having said all that. I will likely make some planes for the next gun. I didn't know there was going to be a next gun when I started building mine, so I didn't need them originally. It is highly likely that making or buying planes for the first gun would not be a waste of money. Building rifles is like eating potato chips, can't have just one.