Thanks guys. Yes, that flex jig worked out rather well.
Continuing on............I decided to locate the hole for the timing gear first and then locate the crank hole relative to that.
Then spot drilled and drilled. I'll have to tap the LH threads later, when my LH tap gets here.
Next was to locate the crank hole relative to the timing gear hole.
With the crank holes drilled and reamed, I could then mount both pieces in the vise and use my height gauge to determine the center of the crankshaft hole. This enabled me to determine how much I needed to mill off the Side Rod mounts.
Next I used my edge finder to determine the horizontal and vertical position of the Side Rod holes. Then spot drilled, drilled and threaded.
Next I turned the part over, indicated it level, then located and drilled the mounting holes.
After making a mounting block, I mounted the parts in the lathe, turned the oil spigot and drilled the oil holes.
Then, after some filing, it was off to the sand blaster to turn the mounts back in to castings again and bolt them on to the base.
I couldn't believe how many operations two, fairly simple looking pieces, required. I learned a lot about planning a sequence of operations with these pieces.
If nothing else.........I now have the neatest looking paper weight here in the Airpark.