Hi Matt,
The solution I came up with when I rebuilt my fridge is I cut a square flange from 1.2mm 430 stainless steel and embedded that in the top of the fridge that receives the lid. I then cut a similar square flange for the lid. I fitted a standard magnetic fridge seal to the flange on the lid. The lid is hinged and seals on all four sides with the magnetic seal. I had the magnetic seal made to fit so there are no joins in the seal: Seal-A-Fridge: 0800 36 77 99 www.sealafridge.co.nz
Although the seal holds the lid closed, I retained the original latch so the lid is latched