Once, years ago--at the Western Nat'l rendezvous in '84--I decided to sew a rawhide cover on a gourd. How hard could it be? I've sewn covers on powder horns and bottles, and sewn rawhide repairs on probably half the MLs I've owned over the years. . . .
There's two approaches to getting a well-fitted cover. You can wrap the item to be covered and try to snip a bit off each edge, so your seam is mostly straight, or you can keep one edge straight and do all your trimming off the other edge: this results in a classier-looking spiral seam. Not that I'm saying anything bad about folks who try to have all their seams in a straight line--I'm sure some of 'em are nice folks--they're just lacking in aesthetic judgement.
So anyhoos, there I was. Got a nice gourd, got a good hank of sinew (elk backstrap, if I remember right), got a nice chunk of well-scraped mule deer rawhide, scraped as fine and thin as parchment. I commenced to cuttin' and fittin' and occassionally stabbing my fingers with the awl. Took the better part of a day to get it to work out right, and the seam line went entirely around the gourd three or four times. But it was a nice job of fitting, no gaps between the edges, no saggy-diaper-lookin' spots. I was right proud of myself. I set the gourd out overnight to take in the morning dew and slow the shrinkage of the rawhide.
Got up the next morning, checked the gourd--looked good!--and set it in the shade with a piece of canvas to cover it and slow evaporation. Long about late afternoon (after the afternoon rain shower) I went to check on my gourd.
Rawhide shrinks. Gourds don't have a great deal of structural integrity. I wound up shaking flakes of gourd out of the weirdest-shaped rawhide box anyone had ever seen. They did all comment on the nice sewing work, and said the spiral seam was classy.
I later sold the box to some greenhorn, who was puzzling how anyone could shape rawhide like that. I've never had the inclination to another.