I have typically reused oil coolers. None of the engines I’ve disassembled have had had disastrously bad coolers. Most have some internal fin damage and Murbella was no exception.
Honestly, I don’t know how this kind of damage happens to an oil cooler inside of the housing. Outside, yes. Inside? Huh?

Now I started this the other day with solvent soaking inside the cooler itself. I replaced that twice.
Today I filled it with acetone again, this time to displace any mineral spirits. However, you can see by the color of the acetone (above) that there is still a lot of old deposits in the cooler.
I may just keep doing this off and on for a few days until it finally runs clean when drained.

I started sanding up the housing, trying to get the old burnt on adhesive from the sealing foam tape off. Normal scrubbing and blades were not doing it so I had to sand.

The base didn’t really want to clean up much.

There are the only fin areas with some damage. I’ve seen worse.
What would be so nice is to have one of those Concept-1 modern aftermarket shrouds that have the spacing to do a larger Type 4 oil cooler on a Type 1. For an FI convertible that would likely make a positive impact on the oil cooling.
Maybe some other time.