Need some hatch advice...

I've been staring at my Galley Hatch on and off for a few days and can't figure out what I should do. This trailer was bought from another person and I'm trying to finish the build and get it ready to camp in. For the hatch I need to seal it and likely put on a hurricane hinge to replace the large basic aluminum hinge that is in place right now or maybe seal existing hinge somehow. The problem with the hatch is that the hatch wasn't formed to match the profile of the sidewalls perfectly / properly so there is no gap for any trim or seals in some places and large gaps in other places. I also found out that the hatch framing isn't square so there is more overhang on one side versus the other. I'd love some input and suggestions if any of you have some. Here's a couple photos of the hatch closed showing the problem areas.

This photo is showing the upper part of the wall and the lack of gap available for trim or seals. I've seen lots of people here cut down the sidewall to make room for the trim and seals. Maybe thats what I should do?

This photo shows the big gaps... they measure about 1/2" or bit more in some places. Also along the bottom of the hatch where it meets the floor there is a large 1/2" - 3/4" gap but that should be easy for me to deal with as it is pretty consistent from side to side.
The gaps and tight spots between hatch and sidewalls are pretty consistent on both sides. I've looked and compared the two sidewalls and they are both cut well and match well so I know the problems are in the hatch. I wonder if it will be easier to simply rebuild the hatch completely to match the profile properly or fight with the existing hatch, or maybe just stuff the big gaps with large seals and find something small and slim for the tight spots.
The hatch is framed with steel tubing that was welded and bent into shape then it was skinned with 1/8" and aluminum. There is also two Maple spars to help support the skin. Here's a photo of the overall hatch and galley space. This photo shows a partially completely galley cabinet / counter which is actually no longer in the trailer as I'm rebuilding them in a different way to better suit my needs.

Anyone have any ideas or suggestions?
Matt
This photo is showing the upper part of the wall and the lack of gap available for trim or seals. I've seen lots of people here cut down the sidewall to make room for the trim and seals. Maybe thats what I should do?
This photo shows the big gaps... they measure about 1/2" or bit more in some places. Also along the bottom of the hatch where it meets the floor there is a large 1/2" - 3/4" gap but that should be easy for me to deal with as it is pretty consistent from side to side.
The gaps and tight spots between hatch and sidewalls are pretty consistent on both sides. I've looked and compared the two sidewalls and they are both cut well and match well so I know the problems are in the hatch. I wonder if it will be easier to simply rebuild the hatch completely to match the profile properly or fight with the existing hatch, or maybe just stuff the big gaps with large seals and find something small and slim for the tight spots.
The hatch is framed with steel tubing that was welded and bent into shape then it was skinned with 1/8" and aluminum. There is also two Maple spars to help support the skin. Here's a photo of the overall hatch and galley space. This photo shows a partially completely galley cabinet / counter which is actually no longer in the trailer as I'm rebuilding them in a different way to better suit my needs.
Anyone have any ideas or suggestions?
Matt