Hi,
Can you post the model number of your fridge? And I am assuming you mean the metal louvered vent cover in the side of the camper, it would be by the bottom of the fridge outside.
I am not sure exactly which metal vent your 83 used. I found some older vintage ones, but I'm not sure they are the ones for your camper.
It would help if you can post a picture of the old one if it exists and or what is left in the side of the camper. Many have a frame that is screwed to the camper in the rough wood opening. Then the cover fits in the frame. You may have to buy the entire frame and cover, but it would solve the problem. And some of the older ones, just screwed to the side of the camper, but not sure Sunline used that type.
And it would help if you could put a tape measure in the pic so we can see the size of the access cover in both width and height, that helps too.
We can help you look, but we need more info.
There are 3 ways to add pics.
1. Upload pics to a specific post attaching them at the end of the post.
2. Linking them in from a public viewable web photo hosting service you have.
See here for 1 and 2
https://www.sunlineclub.com/forums/f105/forums-101-posting-accounts-basics-11235.html#post86041
3. You can upload pics to the forum in your own personal photo album. Then link them to anywhere in the text of a post. See here on how to create an album.
https://www.sunlineclub.com/forums/f105/forums-101-posting-accounts-basics-11235-2.html#post87945
If you still get stuck, let us know. Pic's go a long way in helping show things you are working on.
Hope this helps
John