Everyone who's seen mine* (imported) has said 'Oh, I could have made that for about a tenner's worth of materials'.
One or two of them probably could have, too, so if you have no luck elsewhere, I could re-direct you. Most tailwheel towbars over here are home-built, it seems, so for those with the skill, there's a market amongst those of us without.
*The 'Taildragger Dragger' is available through Skyline Aviation in the States. It fits a Maule and is adjustable.