Egr cooler leaking externally?

[Nilao]

After brushing the built up dirt off of the mating surfaces I found what appears to be a nick in the casting. I found it from following the coolant stain in the aluminum. You can see them in the picture, they look like water rings lol. I'm 100% sure the oil cooler has never been disassembled so this is either a factory imperfection or the coolant cut a groove in the housing. I'm leaning towards a factory flaw though. Will post more once I get the cooler off. I have found a NOS on eBay for $150 to replace it if it's damaged beyond repair. If it can be fixed I'll fix it. I know a guy that owns a machine shop who can do it but it'll be a matter of cost. Might be cheaper to replace it than fix it.