Building a keezer - hinge question

I picked up an older Sears 23 CF chest freezer today. I plan on using it for cornies and to do things like brine big turkeys for Thanksgiving.

I realized after I got it home that it doesn't have standard hinges. The hinges appear to just be inside the freezer rear panel and the lid - they don't bolt to the back of the lid and freezer body like the hinges I've seen here. Has anybody dealt with these before and tried to put a collar on? I hope I didn't really screw up by buying this freezer.

My freebie from Craigslist was the same way.

I bought some regular door hinges from Lowe's and attached it to the back with some short sheet metal screws. I was holding my breath about hitting a cooling line, but I came out ok. The only bad thing (besides dodging the lines) is that the lid isn't spring loaded anymore...but it is fine with me as I don't open it that often.

How did you bypass the existing hinges?

There was a round plastic plug on the side of the lid, towards the back. I pulled that off and the hinge mechanisms were hidden behind there.