Question for the fridgies on here

[Road_Warrior]

So my trusty old Kelvinator beer fridge died recently (ice box got cold but the rest didnt) and I replaced it with a $50 job off Dumbtree. It is an old 1970's pommy made fridge called a 'Thorn-Triumph' with a Danfoss compressor in it.

It works, and gets beers...coldish...but not cold enough. Come early afternoon the compressor is running non stop, the casing temp gets as high as 86 degrees all the while the beers inside are only at about 10 degrees. I should mention the evaporator coils are clean as, and the freezer is very frosty. When I first got it and turned it on, it took nearly 2 days to pull down to a respectable temp and that was with mild 30 degree days.

Is it a bin job, or could there be a fix for it that will allow this little fridge to get it's mojo back? I don't mind spending a little bit of $$$ on it, but second hand fridges are easy to come by also...