You won't get much closer to the X74 than the Atlas PD box car. I've looked into kit bashing an X74 myself, but just haven't gotten the motivation to do it. There are three main things that you need to change. 1)Cut off the roof from the Atlas PD car and replace it with an X-panel roof (PD car has a diagonal panel roof), 2) File the ends of the sill to a 90° angle and 3) You'll need to somehow chisel off some of the raised panels on either side of the door. Once you've done all that, you'll have the closest thing you're gonna get to an X74 without someone making one in plastic. But, the X74 was such a limited car, so I wouldn't hold my breath...
Get to work Dan!
