I agree with using a tire casing for a patch, but I've found that sew-up/tubular casings work a little better, especially silk or cotton, as they're thinner and more supple so you won't get as big a "bump".
I don't mess much with patching tires anymore, I carry a spare tire now. I've needed to use the spare twice in the last 10 years, but when I did need it, I REALLY needed it