Cliffo. I had the same problem with mine. Used 95 x 35mm pine offcuts to keep the profile as low as possible. I just resided myself to screwing the lid into the pine through the top two holes only.
I have my fingers crossed it won't come undone. I always open the lid "carefully". To brace the collar to the fridge I used some double-sided tape. Be careful with this stuff you have to line everything up spot on first time.
Then I caulked around the joint (inside the fridge) with some waterproof silicone. Seemed very firm after this. Just for assurance I cut a bit of slotted angle iron in half that I had laying around and screwed it into the old hole that held the lid.
Seems surprisingly sturdy at the moment. Fingers crossed.
Enjoy your new fridge. You won't be sorry.
Warren -