Powder Coating

Where are you? That will help people make suggestions
Almost any good shop can likely do a real good match, but of course you have to give them something to work with, like a pic or old manifold to show them etc. I had my Spider done (quite non-factory) and after just discussing and looking at samples, they came up with a really nice scheme for me.

Good Luck

Be aware that the "factory color" might not be what you think it is, nor what you want!

We got a new factory manifold for a customer, and it was a bright, not very attractive, aluminum-paint color...

Some of the "molten silver" fine-particle wheel paints are very nice.

Surface prep is key.
Early pc attempts didn't seem to holdfast and people discussed potential off-gassing of embeded material of nuances of the alloy.

One place that has been dealing with 928s specifically in addition to other projects, is Legend Garage in Texas. Of course, you are facing shipping with that option. But he/they will work with you with respect to the surface prep, whether any imperfections are to be machined/filled etc.

No affiliation.

Edit: Here is their write up on their process: legendgarage.com/process/

Geez, just notice April post date- hope it went well, post pics of results!

You need to go to a place that takes their time to do it right for your application. I had mine done and the shop knew not only about the out-gassing but that I needed a special treatment because of the kind of metal etc. It was just a little extra as I recall. He needed a week to get it done because he had to do the baking and extra treatment etc.in order etc. but the result is tremendous and looks like the day it was done over a year ago.

Mine is in Fredericksburg Va however,,, so just some background advice I picked up.

A warning for anyone who is powder coating the intake manifold...

The coating is a good insulator, which means that the temp sensors on the manifold won't work any more. You will need to ensure that the sensors are actually grounded, or the engine will not run well.

Try a search for legend garage or Legends garage in Texas.
First, they have some info on the website about p/cing the 928 parts in particular, that should be helpful.
Second, they have some knowledge of same. Not recommending for refurbishment, just providing a point of info.