Frame welding opinions, please.

The only rust I see in the picture is surface. That being the case more than likely it was caused by one of three things. 1) Mild side impact at the bottom of the frame impacting the kick stand and making the break. 2) Someone abusively dropping the weight of the bike over on the kick stand and breaking it. 3) Metal fatigue from years of being placed on the stand possibly with abuse as in option 2. If it were mine, I would simply knock it back straight with a hammer. Then I'd turn my mig welder down really low and make repeated "tac" welds to keep the heat down in the chrome moly tubing. After that I'd give it a shot and keep an eye on it. There really isn't much else you could do unlesss you're experianced in fabrication enough and have the tools required to replace a section of tube using a tig welder and the proper filler metal.