I got a pair of sharp anatomic road bars into a 3TTT quill stem with a dime in the gap and some twisting. Apply force on the stem towards the center (you know, the way you want the stem to go on) and twist, getting it on a bit at a time. Your gonna scratch your bars but that's pretty inevitable. Also, grease the bars first.

Also, this is the best looking hinged faceplate stem I've seen, the Cinelli Oyster: