Thanks for the helpful hints Lambone. I got it setup down in the local quarry last night for the first time. The key step I ws missing was rotating the end cross bars a full 270deg so that they are under the ledge - it just all fell into place after I got that sorted so I'll be trying it halfway up the wall the next time I'm down there. I know what you mean about packing it away, that turned into a full-on effort with two of us on the ground - thanks for the handy hint on making sure that end cross bars are in the right place to avoid ripping the fabric, I shall watch out for that.
After last night, I don't think I'll have any problems deploying the ledge solo, but in your opinion should it be possible to pack it away again on my own? It wasn't playing ball last night in a strong wind and I was stood on the ground!
Raafie, thanks for your efforts but I didn't get any scans. I'd appreciate it if you could try again. YHM.
Now I just have to convince the new girlfriend that Yosemite is the destination of choice for next years holiday ;-)