You are overthinking this. Just step back and think about what you are seeing:

Dial mounted on crank, dial button on bell housing. If the dial indicator reading is increasing, the button is being depressed, the bell housing is getting closer to the crank centerline. Conversely if the reading is deceasing, the button is extending and the bell housing is moving away from the crank centerline. At the maximum reading or minimum reading, look at what the button on the dial indicator would have to do to bring the reading to zero and that's the way the bell has to be shifted. The amount is half of the total indicator reading (TIR) or in your case 0.014 (+.007 to -0.007).

I hate to throw in this caviate but the + and - readings do not have to be equal. In your case you could have +0.004 and -0.010 which would still give you a TIR of 0.014 and 0.007 offset.