Don't know about the header, but...

Your needle should have a little set screw in it, or at least a threaded hole where one would go. My engines have all come with a braided wire, a set screw, and a round disc to put at the end of the wire for easy turning. The wire can be cut to any length.

An alternate method is to use either a piece of music wire bent into an L shape, or use a spare allen wrench, held in by that little set screw. I like the allen wrench method as it has flat sides for the set screw to grip, has a perfect pre-bent shape, and is fairly rigid.

Here's some pics. Sorry they are blurry; I'm a better pilot than photographer.