So, for the second half of the birthday present I sent to my sister in Australia. I had another go at making a hammered silver clasp. I also made my own spring ends. Both are made out of 0.8mm silver-plated wire (it really is fine when you hammer it) and the clasp also has some 0.4mm wire wrapped round it to strengthen it and to fix on a green bead. Hammering the thicker wire into a hook shape was easy. But wrapping the thinner wire around it was not easy and it's hard to get it really tidy. I expect this is one of those things that gets better with practice.
The nice thing about these over-sized hook clasps, though, is that they're really easy to do up compared to other clasps I've used (probably easier than toggle clasps and definitely less fiddly than lobster clasps).
The necklace is strung on natural leather, with some of the green beads that I was given for Christmas.