Which ones? If they're meant to be seen somewhere other than where you find them, I'll have left the XXXobj.txt file in the Scenery sub-directory and instant scenery should have no problem finding them. The XXXobj.txt file is a listing of the GUID and friendly name that Instant Scenery uses to call up the objects. There will also be a XXXXp.bgl file that Instant Scenery generates for placement locations for the objects. I use the "obj" and "P" so I don't forget what is what.
Save all that, you could probably decompile the xxxobj.bgl and seperate the models into their .xml components, then place them with an .xml file compiled through the bgl compiler.
Seriously, what were you looking to use? I can probably shoot off a quick library.
I've uploaded a few class oriented libraries to Avsim as well.
Jim