I'm not much of a metal worker but my first question would be are you trying to close it with the inside latch/arm attached or not attached? My point being are you sure you are held up on the metal around the door or is something with the latch mechanism inside binding you up?
If you have the mechanism attached I would uninstall and go from there. Also I believe there is a gasket that goes around the door and if that is not already installed the fit will be even tighter and tougher to close later as well.
Lastly are you sure it isn't in the hinges as they could be slightly bound.
When I redid my cowl I regret not purchasing the one with the door in it thinking I could reuse my old door and weld it in, then I realized that it would be way harder than I imagined with my limited welding/metal fab skills so mine are now smooth unfortunately.
Best of luck.
