Subject: Re: [CR]Repair sewups
"The only frustrating part for me is trying to repair casing cuts. I have never found a very useful way to patch the casing so that the tube didn't eventually pinch through and re-puncture."
Ah Daniel, your question takes me back in time. When I was an impoverished teen age bike racer, I survived on discarded tubulars from older riders. By necessity I learned how to repair those discards. Just one sacrificed 220 gm silk would provide me with lots of material for "boots" that could be glued with latex to the inside of a tubular casing to cover and repair casing cuts. Cuts in the tread strip could usually be repaired with crazy glue and/or plastic rubber.
I would repair almost any tubular but soon learned to always carry at least two spares on rides, since the service life of repaired tires was not nearly as long as for new ones.