Unless you are an experienced welder, I'd opt to have it done professionally. My #1 choice would be to GTAW it. You should be able to find a local welder that will be happy to do the work for less than 50.00. If you were local I'd tell you to bring it to me, but the S/H back and forth would be a little excessive.
If you do know what you are doing, I'd run a fillet weld throat to throat with 4130 filler rod.
If you just scratched your head then you may not want to do the work, or it may just be that you were not "school" taught. Feel free to drop me an e-mail if need be.
