I know this isn't going to be very helpful, but I would reckon in the old days, they probably still used a band saw, or table saw. The difference being that they would of been powered by a water wheel, or steam, instead of electricity. There were power tools long before electricity was even thought of.

As for cutting straight without power tools. I dunno. Isuppose some sort of jig would probably be the best way, but I'm no woodworker.

Connor