Cost effective self aligning clamp recommendations?

Any recommendations for cheap but not crap self aligning clamps for a C-Line? The ones in the photo which have one longer arm on the clamp (which aligns with the non folding side of the frame) are only a few weeks old and I noticed the gap is almost gone which means they are rapidly yielding and are dangerous, I'm going to revert to stock until I find better ones. I have the same style on another old Brompton and they have lasted years so clearly they are not all built the same.