I've just gone and repeated your question (See board 6th June) without seeing that someone else (i.e. you) had already asked it.
If anyone replies to me and not you, I'll pass the response on to you too.
The following was posted to me. Any interest to you?
The point of the sacrificial strip is to stop UV getting to the dacron/terylene sailcloth and causing it to go brittle, when the sail is out of use. The sacrificial strip takes the brunt, it is just allowed to deteriorate and replaced every so often. The sunnier the area where you keep your boat, the quicker this happens. In England, if you expect to replace your sails within three years or so, you probably woudn't need a sacrificial strip.
Even if a sailmaker puts on the original strip, replacing it is very much a DIY job. There is no reason why you shouldn't use any reasonably strong opaque material. Sailmakers prefer Acrylic, because it is highly UV resistant and may last the lifetime of the sail. However, this is an expensive material, which is why quotes look high. It can be bought from sailmakers or firms specialising in tents, marquees etc.
It needs to be attached very firmly and is often both stitched and glued, so a self-adhesive material would be quite sensible, but as you imply may need reinforcing with stitching. Obviously the stitching must not interfere with the shape of the sail. Self-adhesive cloth is a bit messy to get off, of course, but I've used acetone which doesn't seem to have caused damage to the sailcloth.
I've never heard of fabric paint being used. The conventional stuff wouldn't stick to new sailcloth, would it? Anyway, its probably not sufficiently opaque, and wouldn't stand the wear.