if i remember -that is a splined shaft? at least i though so on my 1050`s if it was mine- i would try to put a roll pin thru it- if that shaft is super hard- try it with a small end mill
If you were closer I have a 1253 (no engine) you could have the whole thing. It will be to bad tho see it go to salvage.The key in the picture is not the original. I put this one in a few years ago and the problem went away for a while. It is funny that the shaft coupling shows hardly any wear. You would think it would go first being a softer metal.
Thanks for the link to Craigslist.