Well this might be outta left field but here goes. If you can find one of the parts or have one loaned to you there may be a way out. Those
corners are all the same , each one will fit in any part of the corners of the table. If you don't mind them being the stock part from Brunswick
you could have them 3 D Printed. That may sound far fetched , but it's doable and not that expensive if you check around. They would come out
black in color , or for that matter what ever color plastic that you had them printed in,,just noodling a bit.