I have built about 35 sailplane trailers (before giving up on them as anything but a way to delay starvation) and have worked on a number of others, including Cobra, Komet, Eberle and any number of homebuilts. If you just want to replace the tongue (or Drawbar as it is sometimes called), you need to ask yourself a couple of questions:

"Do I want the basic square tube with a hitch only?" If so, go ahead and have a welding shop fabricate the thing. No problem with dealing with the simplified design.

If the question is, "Can I duplicate the AL-KO drawbar, including the surge brake mechanism, telescoping tongue, parking brake and jockey wheel mount? I am willing to bet that the efforts of a welding shop that could do it will end up being MUCH more expensive than just ordering one from Wings and Wheels. (Price on the drawbar with everything except the jockey wheel is $619.) With an average labor rate of $65/hour or more at many welding shops, the cost will most likely be a lot higher when you factor in the fabrication of all of the components. Remember the levers, damper brackets, sliding bushings, grease fittings, hitch, protective boot, surge damper, linkages and so on. This is not a trivial job.

As a matter of fact, the $619 is less than I expected, and I may replace the round tube on my 1981 Cobra with a new one. I certainly can't duplicate it for that!