One of the most satisfying (to me) cosmetic add-ons I've made is a 140 ci badge. Not sure why, as most people under 50 in Oz don't really know what a ci is. But I do (I was born in the 50s) and I reckon a 153 ci badge would be really good. Who'd know? And we could get an urban myth started.
Say Daryl, don't limit yourself to motorcycles. You are into guitars as well so how about a badge I could put on my cheap Garrison G10 that says Gibson or Martin?? The possibilities are endless!!