I liked milesc2's idea of using an existing attache case rather than the metal specialty cases. The metal cases stand out in a crowd; a briefcase is pretty much invisible (everybody carries them, paperwork inside, not really worth stealing) whereas the metal cases fairly scream "expensive tool!".
I once saw a case for carrying some kind of musical instrument that had a large bell shaped bulge on each side. It was the size of a briefcase but was obviously for a horn of some kind. Being as I am musically-impaired I have no idea what kind of horn it was. Evidently not a trumpet as none of the trumpet cases I see on eBay have the bulges.
I'm looking at a firly cheap attache case on eBay now, brown or black, locking, 17 1/2" x 13" x 4" [interior]. I may buy that if I can't find a bulgy horn case.
I don't think many thieves would steal a horn...Not in my city...
