This is a fun model.
Your modifications sound interesting.
I built this model a few years ago
...made a few of my own modifications and added some other models
to create a Walking Dead Diorama
which I also entered in (and won) an online Walking Dead contest.
Please take a look.
https://www.flickr.com/photos/659362...57676565975303
Not sure if I can provide any other help, but don't be afraid to ask.