Motor Rebuild Data Plate

[springbok]

As I am working on all the little things on my M1038 I noticed that on the valve cover it has an engine rebuild data plate.
I have looked high and low for what all the things mean.
One line is piston 30 and I assume that means that the cylinders were bored out and have 30 over piston and rings ?
This a correct assumption ?

 

[springbok]

If this helps.
Figured out that JON = Job Order Number.
Looks like it was rebuilt shortly before it was auctioned off in the late 90s