What should I replace in OM617 rebuild?

[w123fanman]

We're putting an OM617 from an 85 300SD and a 4 speed from an 83 240D into an 83 300D for my dad. Currently, the engine is out on the stand and we're rebuilding it. It ran beautifully but figured it was worth tearing down before putting in the car to minimize issues down the road. My friend pulled it down to the bare block and is wondering what is typically a good idea to replace on these things. The car it was from had 300K miles but it seems like the engine may have been newer than that because it did run well. Note, we will use OE gaskets and such to avoid having issues down the road.

So yea the few basic questions:

What should I probably look at replacing/resurfacing/whatever?

What are things people might overlook doing this job?

Are there any brands to stay away from when considering these parts? I know to stay away from the Victor Reinz head bolts and Febi tensioner, anything else?

Any general advice?