I did this for the build off nine this year. It's a mid 40's cwc frame and a mid 50's briggs 6bs. I am starting on a Worksman pedal power next. I love the bare steel frames and in AZ rust is not too much of an issue with a coating of wax.
I liked this one so much I found another frame and making two of them didn't want to give it up for a motor. So I will have one with and one without when I get to it 62 Rollfast Hawthorne twin bar
There was a guy on here called Crankset Leather that was making seats, and other bike accessories out of leather. He was a third generation leatherworker, and it was high quality. His seats were only 90 bucks! He later changed the name to Skiptooth Leather, and got a website. But his site is down now, and so I'm not sure if he's still doing it or not.