This is possible, but tedious. Here is a simple tutorial:
1. Import the age using the PyPRP age importer. Look on the wiki if you don't have this installed.
2. Save the file and open with Blender 2.49b.
3. In the book text file, change the sequence prefix, and change the main page number to 0.
4. Delete the scene called 'Scene', and rename the other one to 'Scene'. Yes, I know I said scene many times in the previous sentence.
5. Select one of the objects in the imported age. If it is supposed to be solid, set its bounds.
6. In the Links and Pipeline section, delete the existing material, and click on the 'ME' button.
7. Add a new material. For the texture, use an image.
8. This is the tedious part. Use PlasmaShop or something similar to export the textures for the age that has been imported. Try to figure out which texture should be used on the object you have selected. Texture the object.
9. In the Link and Materials section, delete all vertex groups.
10. Repeat steps 5-9 for all other objects.
11. Copy the Python .pak file for the age you have imported. Extract the copy, and edit it as needed.
12. Edit the age as needed.
13. Export the age.
I am working on a repaired instance of Tetsonot, for those who hate the dark, damp place. I am also working on restoring the outside of Payiferen.