Toyota ribber is missing its table clamps/brackets

I own a Toyota knitting machine KS 901 and I recently found the matching ribber KR 501. The ribber is a bit in a rough shape but it's fixable. But when I tried to connect the two I realize that the ribber clamps that came with it are the wrong type and they don't fit right.

I've been looking everywhere for replacement clamps but I find very few. On eBay they're usually in the UK and they won't ship to me (I live in Belgium). Or I find generic clamps but I don't know if they'll fit my ribber.

Is there another place online where to find those? Or does anyone have the measurements for these particular clamps so that I can see if any of the generic ones match?