Franklin Frames Custom, Rivendell Bombadil, '83 Specialized Stumpjumper
I use the Problem Solvers ones shown one two bikes. On one, it's attached to the outside of the quill stem as it's on a American Classic HS, which doesn't allow for spacers.
The other, it's a part of the stack of the threaded headset, where it doubles as an extra spacer. The noodle part is what set these apart from others, I've used them without it and these are great because the angle of entry is variable. You don't need the hanger to be threaded to be a part of the HS stack.
Here's the outside mounted one .....
I never learned to ride a bike. It is my deepest shame.
The headset mounted fork hangers sometimes result in brake chatter when used with a less-than-totally-stiff fork... and the remedy is to replace with a fork mounted hanger. Also, the fork mounted hanger is more similar to the setup that was normally fonud on suspension forks like your marzocchi, so it *might* make the change easier.