If you find an alternative delay line (in an old TV perhaps), make sure that it is a high impedance part (1 - 1.5K) otherwise your circuit wont survive very long. You will also have to adjust the values of R8 and R13 to suit the impedance of the particular delay line you intend to use. I was unable to source either of these parts, so until I find another solution, I will have to live with jagged edges.
The MC1377 is a rather dated component. Since then, newer and better ICs have been developed which produce a much better picture quality. The schematics for a converter based on the AD724 can be found here: [[RGB_SVideo|AD724 Based Converter]]