I purchased a few aircraft templates from http://makecnc.com and they are pretty good. They come with several file types and sizes and have decent instructions. These are my two favorite warbirds. I had to move things around and make minor adjustments but now they fit perfectly in the 300mmx200mm bed.
Could you them with us?
Those are very nicely done
I actually measured 320 x 230mm for the k40. I wonder if there are more derivatives on the market besides the power supply versions.
@Paul_de_Groot I’ve only tested the maximum cutting area by adjusting the max dimensions in the settings and I get 313 x 224. It seems like the starting point could move an inch up and to the side, adding another 25mm to each dimension but I don’t know how to do this.
@Jose_A_S Sorry, I can’t share the files per their terms. They’re well worth the cost, though, and I like the idea of rewarding the creators for their work. This is the link to the F4U. It’s 9.95 and other models are cheaper and some cost more. http://www.makecnc.com/wwii-the-vought-f4u-corsair-plane.php
If I buy the template, could you share with me your modified template for a 200x300 machine? 
@Jose_A_S I’m sending them an email request with this question. Their copyright terms say I can’t share any files but it never hurts to ask for special situations.
@Jeff_Johnson thank you Jeff, let me know what was their answer, please
@Jose_A_S I got the reply and they do not allow sharing but will include my modified files in their package. I am going to clean up the files, add a few instructions and submit them. I’ll let you know when the model includes the new files.