On a related note, i found a similar situation with free skyscraper models on a forum in skyscrapercity website. I'm slowly starting to gather them together to host on a suitable storage site.
Great idea to create a generic concept for building different Ties. I was thinking of doing the same thing, i just had to decide which model to use as the template.
Not sure if it is bundled with Windows 7 but theres a handy tool called Snipping Tool which I use at work to select any part of whatever is on screen. I then dump it into Paint and manipulate it there. Simple and very effective.