Welcome to the new and improved Proflex / K2 Tech Forum!
to be honest I've been wondering if it isn't as easy as getting a block of aluminium from your local scrap metal merchant and shaping it yourself with a hacksaw and a file... may take a little while but should do the job. Bit of a bodge but should be strong I would have thought. That's what I'm going to do. Same way to make rear disc brake adapters too.