Hey
I am also working on similar requirements. I have lot of scripts running on NT environment and have to migrate to Solaris environment.
The following is my points of observation
1. List out all the scripts.
2. Work on one by one. My observation is if the script works on one platform it should work on other with slight modification.
3. Check for paths (// or \\)
4. Most of my migration solved once I looked after path.
5. Though use strict or use warnings helps, you should first understand what the script is doing and from there have to change. Since the developer has left. This way future maintenance will be easy.
Hope this helps