My confidence in the washing machine was well founded, this morning I found the strap had felted to pretty much the right length, if anything, shorter than I thought. Now I only have a tiny bit of my first fleece left.
The flap at the top was intended to close the bag, but seeing as how the bottom seam gave way, this evening I have sewn it in to form the base. Happily, I have some fine spun wool from the same fleece left from sewing up the seams of my first jumper. The strap got sewn on too, this thick felt is nothing if not sturdy. The texture is gnarly, more like something I dug up than a chic accessory.
I did need a way of securing the top so stuff doesn't fall out if I run down hill or climb rocks. I have been caught out in the past by a loose mouthed, open top bag, racing back to the beach in a muck sweat to retrieve my car keys just before the tide took them. Since I have a collection of stones with holes in them - naturally, every home should have one - I used two as buttons.
So, here is the finished bag. It has a bit of a grim expression. Since it looks like something that would lurk at the back of a cave, I shall name it The Troglodyte Bag. Doubtless everyone will want one, but after the last couple of days, I think it will remain unique.