Cat chassis Is it a xl or xls
 

I know they are basically the same chassis I have this and I now think it came from a xl is that correct and can anyone shed any light on it thanks
http://i1345.photobucket.com/albums/...ps9iduedau.jpg
This one a bit rubbish but it's all I have at the min as they are at work
http://i1345.photobucket.com/albums/...psnkyskijz.png
The idea was to basically build a xls from this how hard will it be

Looks like someone has just made it as a school project as I'd did when I was a kid...