Drill small holes in corners of the doors you wish to remove.

Use a jeweler's saw to cut the doors leaving a small bit of the top, bottom & both sides of each door.  Then use a small file to cut out the doors to the edge top & bottom.  If you try to cut right on the edge and at the top & bottom you will probably end up taking too much material off.

Measure carefully

The Cannon doors represent those found on "Second Generation" EMDs, GP35s through the Dash-2s, so they aren't necessarily the same size as those used on earlier Geeps.  And you can't assume the doors on a model as old as the Athearn "blue box" GP7 are the correct size either.

I drill small holes around the perimeter of the door opening, lots of holes, then connect the holes by pushing an X-Acto blade into them.  Finish with small files.

Take your time, measure twice, cut once, cuss, keep some strip styrene on hand to fix your mistakes, and you'll do fine.

Scott Chatfield 

Doors

Possibly instead of cutting out each door individually, why not cut out all the doors in one section and replace with a panel constructed of thinner styrene and the Cannon and Company doors. The tall doors next to the prime mover would be one panel, the short doors under the radiator would be another. NOT for sure if this would save you some tedious effort, but assembling a panel using Evergreen styrene and the doors may have merit.

Going one step further, you could then look at making the locomotive shell scale width instead of being the blue box wide body.

Simple projects and ideas can always be made much more complicated!

Your replies

are very much appreciated gents.