Swirl patterns in metal sheet?

Not sure but it certainly doesn't look airbrushed. Most likely done in 2 or 3 colors by hand atop of the silver.

I have used two ways.  In one case I made a decal of light gray swirls to put over aluminum painted cowl.  If I remember, this is how Revell did it for their 1:48 Spirit of St. Louis kit.

I also did a Fokker monoplane recently, where I painted the cowl with flat aluminum paint.  I cut the tip off one of those pointed end toothpicks, to make a "stamp" the diameter I wanted the swirls to be.

I then took a bottle of gloss silver, and shook it thoroughly.  I took off the top and laid it upside down on bench- a thin layer of paint remained in lid. I dipped toothpick into that paint and used it as a stamp to stamp the swirl pattern around the cowl.

Also, the reviewer explains how he did it in the link you posted.

Here is what the reviewer posted in the link you provided:

"Now for the reason I have not built an E.III since the 1960s. Fokker cowl squiggles. I tried something I had been thinking about for a while. I painted the aluminum parts a coat of Testor's small bottle aluminum. When this had gotten dry enough to handle, I painted the squiggles with a pointed brush. I used Testos Metalizer, gunmetal flavor, and it turned out to be a bit dark. I recommend titanium or steel. The lacquer based Metalizer flows on and bites into the enamel. This helps in keeping the squiggles from running where they weren't put. Use a half loaded brush or the thin lacquer will run too much onto the surface. The hardest part is to keep the squiggles fairly random. Try not to repeat the same shaped squiggle too much. A couple of coats of Future to seal it and it looks pretty much like the photos."

Also, welcome to the forums!

Thank you everyone for your responses. Yes i had seen that method on the guys page but i thought maybe there was a better one that is used more frequently. I guess i will go with that method then 

Welcome to the forums.

Also people have tried (with varying degrees of success)  to use foil and a small diameter  (tooth pick cut to size) and carefully twisted it on the foil to create the marks….. Seems to be a really hard way to go, to me.