GB... Try: http://cmsnl.com/
Of the MANY 450's I've owned/worked on, I never saw anything attached there (unless I did it... Awesome mount for an oil cooler...)... I ASSUME it stiffens the tab for the steering damper and originally bolted to the jig (at the factory) while the frame was being welded together, or supported the frame on the assembly line so the front end could be assembled on........ Maybe Bill knows?.... Steve
Sorry for the delay - bad news here, I've been pretty distracted. My aged dad had another stroke, this time it blinded him. He's having a very risky procedure this evening to attempt to clear occluded arteries feeding his brain. The end may be near, so if I drop out of sight for a while, that's what's going on...
Ray is correct - it's for mounting the big ol' crash bars that the P model used.
Back in The Day, some aftermarket crash bars used it too - most didn't.
But the P crash bars had a bunch of lights and sirens and crap mounted to them, so they were much "taller" than normal - see the photo below, it shows it very well.....
As far as I know, all the US model P's were 4-speeds, so you should probably see this feature on all 450's, as the frame received only minor changes when the 5-speeds were introduced.....
But very early Bombers may lack it, as they were made (probably) prior to the P's conceptualization and execution.
I'm not well enough versed in the very early Bombers to say for sure - maybe Chris knows??
Ray mentioned something about a K1 P-model - never seen one of those, maybe it was a UK thing ??
In the photo you can also see the tach drive "plug" that the P-models used.
Interestingly, this siren was mechanically driven by a cable - had a little wheel thing that rubbed on the rear wheel when engaged, much like the little lights we used to have on our bicycles (no cards in the spokes on the P-models, though).