GET Speedo Brackets! I have a guy who laser cuts the main piece, I then cut a little more, drill and hand-bend them into 2 different types. One for short stems (password/bmx style) and one for tall stems (mountain bike style). These are intended for stems that move the handlebars forward. They are made of steel. You can use the rubber pieces from your stock bracket/handlebars or use wide washers for more adjusting and a tighter fit. You will need to paint them and get a 10mm nut and bolt. Note: They will oxidize without paint.
$31 shipped to the 48 continental states. $37.50 shipped to Canada.
The one on the left (Version 1) is for short stems. The one on the right (Version 2) for tall stems.
Version 1 on a bike
Version 2 on a bike
What they look like now: