A graded fox ejector forend can be converted to sterlingworth type by adding a piece at front of iron that Fox used on first sterlingworth 12 gauge ejectors. Then you would have to add the little roller in slot and make a new wood forend. Look at Dave's article about sterlingworths in Double Gun Journal back issue and you will see the piece that was added to extend graded forend iron. I have the piece but only have one. Bobby