Here's the raw holes, there is a hole drilled up through the existing hole above, the one created by the meeting of the 2 drillings for the cylinder hold down studs. The hole is drilled up through to the hole for the case bolt. It's what you can barely see in the previous picture.
The ends of the tubing are soldered shut, then the hole drilled with a # 61 drill bit. The oil should be directed in a manner to miss the rods and wrist pin bosses and hopefully hit the inside of the piston crown. Time will tell.