Phil made one for us, from memory we didn't have the "correct" aluminium edging but he being of technical mind used a piece of right angled strip with a couple of washers as spacers and he re-purposed one of the under bed plastic brackets as a support. Due to the slope of the van walls it required part of a wine cork affixed to the extended end to make it sit level. I'll dig it out of the van next time I'm in and try to get a photo uploaded.
It's another of his what he calls "elegant solutions" to minor shortcomings with our Eriba, The latest one is the very strong but small magnets he's fixed to the drop down extra worktop thing that collapsed every time you breathed on it. He's quite ingenious
Denise & Phil