If you have basic painting skills with Hammerite you won't see any brush marks, because once you put it on and feather it over it reacts, hiding all of the brush marks. That is why I initially chose it, as I have a long experience with it (painting bikes growing up as a kid).
It's all about the feathering. Put the paint down (not too much, that takes lots of practice) and then leave it for about ten seconds, then feather it over in the same direction. Then just leave it to do its thing.
TBH? 90% of what I have painted will not even be visible once the case is back together. It's literally the "frame" around the PC. So that is about all that will seem different, as the interior is going to be pretty radical.
Here. I thought I had uploaded this earlier on this forum but I guess I forgot (too much going on in my brain !).
It has like a pearl sort of mixture in it, and what appears to be a very fine gold flake. That pic is the best portrayal of how it looks IRL IMO. It is very hard to capture exactly what it is you are seeing, like many paint effects.