2 of my guns require using the top lever for closing. I was cleaning the above gun (a 1908 manufacture) and found that opening it is much more difficult than any of my other Parker guns. In order to close the gun, with or without shells in the chamber, I have to operate the top lever. I have the same closing issue with a 1904 manufactured VH Parker. My other later built Parker guns close on the receiver without having to operate the top lever. Ideas??