S130 diff cooler:

In the States they just stuck on the finned cover and called it good.  The 300ZX's got them with the LSD diffs, CLSD for sure and I think the 88 Shiro VLSD.  Only 87-89 I believe.  The FSM shows maintenance procedures on the CLSD's but no pictures of the cover.  It's one of those things to look for for those trying to get limited slip for their early Z's.  Like finding gold in the wrecking yard.

Here's a typical finned cover.

https://bringatrailer.com/listing/1988-nissan-300zx-43/

But this one looks like it might have the plumbing for fluid cooling.  Different cover.  First time I've seen it.  Interesting.  

https://bringatrailer.com/listing/1989-nissan-fairlady-z-2/

Yes the Shiro VSLD's had finned covers too.