Well, I wound up just welding in a block of keystock. I was being lazy that night, and figured even though I feel my adjustable bolt/jamb nut idea is a good one, it would have taken longer to do. I had to hurry and get it ready to test on Sunday, so I welded in the key stock.
Didn't get to test it due to the weather, but I found a problem when hand cycling. I trimmed the ejector too short/narrow. It was only hitting the shell base, if you pulled the bolt towards the left as you pulled backwards. If you pulled straight back, it would just barely hit the casing, enough to strip it off the bolt, but not enough to actually kick it out of the receiver. Then of course the casing would hang up the action. I need to add weld material to the ejector this evening. Glad I found it now, rather than at the range. I hate the weather wasn't co-operating, not to mention that I've got the start of a sinus/upper respiratory infection going on. Felt like crap all day yesterday. Maybe next weekend.