Not my finest hour. Then an hour later...
I finished up the desk for my sister-in-law this evening. I had a couple of setbacks this afternoon, but it is often said in woodworking that it's not how you mess up, but how you go about covering up your mistakes.
The top connection for the sliding lid support outsmarted me today. I checked the new hardware with the old hardware and they appeared to be pretty close to the same dimensions. I proceeded to use the existing hole to mount the top support of the arm. Well, it sure did support the arm, but the lid wouldn't close! Bang head against workshop wall.
So, I figured out where the mounts SHOULD have been without having to relocate both holes (only one on each side). Keep in mind that these were pretty big holes to accept the brass inserts, so filling the "extra" one posed a bit of a challenge. Perhaps I could just tell my sister-in-law that there's a bonus hole in there. No. She's pretty smart and that's pretty dumb.
Oak secretary, meet oak dowel. I enlarged the holes to match the 1/2 inch dowel I had laying around and put some plugs in. A little patience with the flush-cut saw and some dark stain I had laying around and they are no longer mistakes. They're "features". I seem to have similar "features" in a lot of my work.
The hardware is now installed and we now have a good, stable secretary.