The frame brace you mention was on the smaller Crusader series frames (unit 250 engine) and not on the twin frames. Note the top tube on your frame has a lug for the cylinder head steady, and the tabs for the battery back plate point forward, unlike models with a toolbox where the tabs point inwards. If there are tapped holes on the rim of the front hub, they are for the "bacon slicer" discs. If no holes, someone has traded front wheels.

See the online parts book on Hitchcock's website.