Heki 2 skylight, replacement help please!

I have a 2008 Northern Lite camper. It has a Heki 2 rooflight (skylight, hatch, roof vent, whatever you want to call it) in the cab over area. I recently purchased this camper used and the previous owner told me that this skylight was damaged because a tree branch had come in contact with it. Anyway, the clear top cover has a crack and one of the white hinge areas is broken where the black vertical hinge attaches to the white part of the hinge at the very bottom. It looks like this white part is one continuous piece and is part of the plastic molded white portion on the whole lower vent frame, and not just an easily replaceable separate part (a very poor design if you ask me). I have tried to get separate replacement pieces but to no avail. Everyone I have spoken with says I have to purchase a whole new skylight assembly, for somewhere around $600 to $800±. Anyway, what I think might be a better approach is to just replace the whole thing with something else, a much less elaborate, less prone to damage, and less expensive type of vent. Does anyone know of any type of hatch / skylight / vent that would be a good replacement “for the existing hole cutout”? Or, does anyone know how I could re-size the existing cutout to make it able to fit something more common? Thanks in advance for your help with this.