It looks like the BC23 slides and attachment are exactly the same as on the BC26 - if you look carefully in the slots on the bulb part it probably says 'Bainbridge' on one side and 'A017' on the other. As mentioned on the BC26 version of this thread it seems that these break on a pretty regular basis, I think they're just not strong enough for the job basically. I don't think U/V is to blame as they spend most of their lives under the cover, and I've had a couple of virtually brand new ones break after only a few outings. The A107S version that I've replaced them with have survived much better, no breakages after a couple of seasons, although they can get bent, so it shows the sort of forces they're dealing with. The one that seems to suffer the most is the top batten slide, as this is the one that gets pulled furthest round when you ease the sail off-wind combined with the stress from the batten. I've just replaced this one with a Bainbridge A032, which is sold as a boom outhaul slide for dinghies, but it looks like a good stronger alternative to the A107S. It's longer than the A107, but as I'm only replacing one then the stack of slides still fits inside the boom cover (just). Haven't sailed with it yet, we'll see how it gets on - probably pull the mast track off instead of bending now!
Regarding fitting, it doesn't require a great deal of sail making skills (I don't claim to have any), although you do need a proper sail making needle and a palm to push it through (plus pliers to pull it out the other side). As with most things there are a few YouTube videos to show you how. What makes it considerably easier though is the toy that Santa brought me this year in the shape of a 'Speedy Stitcher' sewing awl. This clever gadget is basically an awl with an eye in the pointy end to take the thread. You can push it through the multi layers of webbing very easily, pull a loop of thread through and pass the loop back over the slide so it's on the same side as you started, then pull it tight, and repeat as many times as you fancy. I reckon I can now replace a slide in less than 5 minutes, which is a lot quicker and cheaper than sending it off to a sailmaker! If you can't re-use the original webbing you'll need to get hold of some. I initially tried the cheapskate option of B&Q's webbing, which lasted a season or so but one or two actually chafed through. The proper stuff is tubular but I found it difficult to get hold of and eventually found some dyneema webbing at a reasonable price, so trying that now. The idea of avoiding all this palaver by using sail shackles is interesting and I'll be interested to hear how well they last. Very easy to replace though, could even do it at sea if necessary.
Sail life - mine are 4 seasons/5 winters old now and still holding up pretty well. Having said that, I have just had the sacrificial U/V strips on the luff and foot of the jib replaced by a local sailmaker (Westaway in Ivybridge) as the originals were shades of green and black. I should really have taken the jib off over winter but have perhaps been overly optimistic about the number of nice sailing days in winter.