Rex, I have had good success with brazing castings where maching needs to be done. I would grind out and buff the inside of the hole and the outside surface to remove any contamination. Use pre and post heat and take your time. This part looks rather small so I would also pay close attention to the temp while brazing. Pre heat to 400*F, make your repair, I do not let the piece get over 600*F "interpass temp", for post heat I bring the temp down 100*F every hour shutting the oven off at 200*F. Just my process that my dad passed on to me and what I have used many times with good success.

I agree with the brazing and if that hole wears often it may stand up better than using cast iron rod.  Or bore it for a bushing.  Nickel rod or mig is very hard to machine even if you get the machinable type rod.