First off, thanks to all for the ideas and support. Did the repair on Monday and the cam has not moved. Original plan was to replace both set(grub)screws with grade 8 hex bolts and jamb nuts. Due to tight clearances I was only able to replace the larger bolt and left the screw on the key as it was. Also used some Loctite retaining goo on the shaft. The hex bolt made a big difference in the amount I was able to tighten it. Has a good bite on the shaft now. If it were to move again I would consider one of those pointed bolts with a divot drilled into the shaft. So we're back up and running and all is well in printing land once again.