I just procured an original dust cover for my early Type 38 on Ebay. Everything looks as it should. It has the machined bracket inside that is riveted. It has the symmetrical/straight hole for the bolt handle. It has the serial number stamped on the end. But it measures 5-7/8 inches. I thought that Type 38 dust covers were all 6 inches and the Type 99 dust covers were 5-7/8 inches. Thoughts?