I was wondering about a scale model too the other day, as I like to build them, but I was considering using it as a test bed for painting schemes..before I did full scale. The closest I've found so far is the Yamaha Virago XV1000 at 1/12th scale. Here's a link to it:
It probably won't remind you too much of the Vulcan though, except for style..engine is way diff than ours. The only other one that's close is the one Mazdaracer posted.