Thanks, all, for the kind comments.
After a brief hiatus to work on my mill / drill and add DRO's on the x and y axes, I got back to work on my engine today. I finished up the two connecting rods. Here in the first picture you can see the fixture I made to hold each connecting rod for machining.

I first milled the edge of one side, then took out the screws, flipped the rod over and did the opposite side. After finishing the edges on both rods, I changed end mills to a 3/16" and milled the groove down the center of each side. Finally, I rounded the outside edge of the small end.
Here are the finished rods...

And an idea of what they will look like on the engine...


The whole process was a good exercise in using DRO's for positioning. Makes for much more precise locating than trying to machine up to scribed lines and marks.
I think I only need to make and install the crank arms to be able to test the engine. And of course I'll need to make a base for it sooner or later.
Chuck