I purchased this vise today for $50 at a local flea market. I planned on buying new jaw inserts but everywhere I've checked shows either a T or flat Jaw held on by pins for a Columbian 504 1/2. Mine however are U shaped inserts and it appears they are not available anywhere. Can anyone help me locate replacements? I'm awaiting a response from Wilton. Thanks! 2 screws hold the inserts on