Adding Additional Fld data to an Existing Fld 2 Finish File

I have a topo done, using fld to finish. Now the engineer needs a little more topo, only 200 additional shots farther down the street.
How is the best way to merger the topos?
Do I keep the coordinate files separate? Or should I merge the coordinate files?
I'm going to open the new fld data in a separate Carlson file and create a tin model, and then try to merge the dwgs, but I'm not sure this is the best way to proceed.
Thanks
How is the best way to merger the topos?
Do I keep the coordinate files separate? Or should I merge the coordinate files?
I'm going to open the new fld data in a separate Carlson file and create a tin model, and then try to merge the dwgs, but I'm not sure this is the best way to proceed.
Thanks