"Merging" and offline and online copy of cs-cart

Since an upgrade to 135sp3 I decided to rebuild the categories that I use and make various other changes.

Doing this on an offline copy was really fast and made the process happen so I decided the best thing was to push ahead with doing it this way - starting from a copy of the online site - and then to replace the current online cart maybe losing a few registered customers and sales details or maybe trying to export them across.

Due to other issues at work the process has stalled and will not now go ahead for another few weeks at least.

This means that when the time comes there is going to be quite a gap between the two sites in terms of sales orders and customers. Measured in terms of 10’s.

So when I upgrade the live site. Is it just a case of exporting the new customers and orders from the old site and then re-importing them into the new site or is there more to it than that?