I just bought a 21mm emblem to cover the top of my now-epoxied-over gas cap key cylinder. It is BMW part# 51142308800 and is a tiny but very nice emblem properly used on cases and racks of later model K & R bikes. (I love the Max BMW parts fiche. Type in the part # and up comes every techincal drawing for every model the part is used on!) I was pondering getting 3 to do the carb tops too,but at $7.63 each (before the Chicago 20% discount), I decided to settle for the one and go with the silver paint on the carbs.
Like most everything Airhead, Snowbum has a great technical article on emblems. I took his advice and got a couple of 70mm tank badges that are actually automobile hubcap trim pieces. They are nicer than the true tank badges and less than half the cost! [smiley=bmw_smiley.gif]