Thanks for the photo rappleby that has helped my understanding and is one of the clearest photos i've seen. thanks for the advise from others as well.
It has inspired me to have a go at making a set of webbing myself. I have an ordinary old canvas type belt, some lengths of 2" and 1" nylon strapping and a fairly large quantity of 12oz cotton canvas hanging around - i think i can knock something up with that. I have an old swedish army pack which the straps rotted and snapped off (they were leather and not looked after at all) so i may incorporate that as a 'large' pack...
don't forget to post the photo's when you're done!