After looking all over the internet, I came to the conclusion that I wasn't happy with any of the train beds available. The only one I did like was super expensive. So I decided to make my own (I used a picture of the one I found on the internet to get approximate dimensions).
The bed is made out of 1/2 inch MDF, railing and trim is made with pine. All edges of bed are routered (except exterior edge of round part). I painted in latex paint and covered with acrylic satin gloss. Bed comes apart in several pieces...as all together it would weigh about 350 lbs and be unmoveable.
Major Tools needed:
3 - 4x8 1/2" MDF
4 - 1x4 Pine Boards
4 - 1.3 Pine Boards
6 Lag bolts
Go buy a mattress and measure the dimensions. Then make the top part of the bed where the mattress will rest in. This is pretty simple to do. I used some L brackets for support on the inside corners of the bed. Used a brad nailer and glue to hold it together.