[Kevin in NJ]

They were balanced separately as best I can tell. Some of what I read and what I have been told, but I have not read actual documentation that proves this.

The crank was precision ground. The flywheel located to less then .001" off center line from the mains. This is the first important consideration. Most cranks ground today are not that close, some people consider .002" ok. We have one as far as .008" in our pile of cranks. (we have like 30 engines).
The crank was balanced to 1/4 Oz. Info on the flywheels is no so detailed from what I know. I do know that NOS Ford flywheels from the 40's were not well balanced. By this time Ford would have contracted the work out or not cared so much it seems. This is from someone who had balanced a few NOS flywheels known to be 40's production.

The rods were made to a certain weight at each end +-1 gram. Factory piston/rod assemblies were within 4 grams of each other. The standard today seems to be rods +-5 grams total weight.

For perspective, please do not hold be to exact details, when my brother was researching balancing machines (he has a crank grinder) to figure out what to buy. One of the companies told him that the flywheel for your basic chevy V8 needs to assembled with the same side up. Just the slop in the bolts is enough to introduce 20 lbs of inbalance when running on the car.

So imagine what a 60 lb flywheel can do with an extra .001" off center.

If you want a nice A engine you have to be anal with the balance of the engine. It may be a simple engine, but it is really a precision built simple engine.