That's pretty much what I would do. You'll have to watch for check history and perpetual history. Might want to shut those off, roll them back as far as possible before you run that last closing.
One thing you will want to check is the state reporting and possibly FUTA (I think). I know in MI, acquiring the employees of another entity will transfer rates for state unemployment. It also transfers the YTD maximum wages as well. In Sage, if you purge that YTD data, your earnings will reset and the state reporting would be incorrect. If there is not a bunch of employees, then you probably don't have to worry and those forms are simple. If there is a bunch of employees and you are using Aatrix for the filing, that could be something you need to address.