Initially, I was using a formed sheet-metal hidden hinge for my oil door. Similar to a number of products available from experimental AC suppliers. I didn't really like this solution. I thought there was too much fles in the hinge system to work with my push-button latch. I designed a new hinge that works much better. It works very well. The final version incorporates a spring to hold the door open. Total weight is only slightly more than the Vans setup, most of that is from the latch.
