Actually, there is more to these bars than just longer tubing in the handle grip area. The cross bar itself is set back a bit further... a modification much more difficult (but not impossible) to make. You could probably just cut the ends off the bars, cross-bar and all... drill new holes for where you want the cross-bar to be, and weld the new extensions back on. With some skilled welding and finishing, this could be done to where nobody could tell the difference from originals.
DS