WhiteOut, the stuff for covering typing errors in the olden days, works well for marking the "frets".

I once rigged up an old-style golf cart, (the hand truck sort; not the motorized vehicle,) to hold my bass. A friend turned me onto the idea. He said that it would come in handy when playing festivals, etc., where the parking lot is always a long way from the stage. The one I customized had nice, big wheels. I attached a length of copper pipe sideways to form a cradle. A few bunjees in the right places and it was good to go!