Good idea for a thread, one that could be handy for me in the very near future, but I'll try and contribute to too.
Can't immediately help you, having been in a very similar situation, but my post on the cheery Friday thread from last week might be useful as an alternative solution if you have some that just aren't long enough? Not the bit where I mutilated it with an angle grinder and a welder, but where I put a little brass tube in as a spacer. Not sure if that would work for you... the ones in your pic being flat, rather than right angled to take a bolt through the fork crown brake mount. I had the bit of tube lying around and it happened to be almost the perfect length - you can buy short lengths off ebay for not very much at all, as I did to make some spacers for stair rod fittings that had to go over a thick carpet. Other materials (presumably) available.
Since I'm here, I'm about to make some of these out of a bit of stainless sheet, since they're out of stock everywhere, unless someone has a pair?
