I am converting a bookmobile and it has some significant differences from a standard school bus. First of all, it's square instead of rounded across the roof. It's also made of aluminum instead of steel. And it has a driver's door.
Someone asked me to post pictures of the driver's door so they can see how it is put together and maybe add one like it to their own conversion. If one person is interested, someone else might be, so I'm going to post them all on this thread to make this easier for people to find in search results.
If you do this, make sure to avoid tinted window glass. I hate this and I'm going to get the tinted glass (and, in this case, one piece of plexiglass) replaced with clear glass.
You're going to need grab handles on the exterior wall and inside the door to climb in. It's a tall step with no stairs. What I didn't get a picture of is the hole-step cut into the wall below the floor level (although you can see the top curved edge of the hole in the picture above). Without that, there would be no getting into this door.
These doors are about 2-1/2" thick. Too think for standard deadbolts and door hardware, so you'll need specialty hardware or you'll need to improvise. All these parts came with the vehicle as part of the original coach build-up.
The latch is a very heavy duty piece of hardware. These "claws" grab the jamb-mounted catch bolt from two sides.
Jamb-mounted catch bolt.
Most corners of the door (and the entire vehicle, for that matter) are made from aluminum angle iron. The interior of the door is solid plywood: very heavy.
Door jamb detail. The horizontal part of the bottom extrusion is level with the interior floor. The door is so thick that I had to cut back my new insulated flooring to get the door to close, so keep this in mind if you build your own door.
Interior structure detail. (Green stuff is glue residue from original wall structure.)
Door latched closed.
Interior structure detail, upper front corner.
Interior of closed door.