Your descriptions on both questions are somewhat vague:
1.) if your talking about the system (the person paying for the upgrade) redesigned all MDU's as an afterthought and are looking to you to correct maps that you've already done, I think you should get paid in addition to the original work. In other words, come up with a re-draft rate or a re-draft per unit and present it in writing to the bill payer. If you have to return to each unit for feild verification, get paid for that also. It may be as simple as billing the same rate again, but usually there is less work involved in the return or go-back work and therefore could be expected to do it for less.
2.) you'll have to give me a better description of the addressing work.
Be fair and be prepared to negotiate so you don't lose your job or contract.
hope this helped
