Make em yourself.
A Piece of 1 or 2mm thick stainless plate, whatever size you need. Lets say about 50mm long and 15mm wide. Fold it over on it's self (so it's about 25mm long) then drill to the desired tapping size, open one of the holes to a clearance size and tap the other side.
Looks Slow but is Fast
Member of the ebay Blue RIB cover club.