Try to validate the file using the w3c validator validator.w3.org . I've worked with tcpdf before but I gave it up because it didn't seem reliable. You can also try wkhtmltopdf binary (only if your hosting allows you to use proc_open proc_close ).
Seems a little more stable to me. It also has a PHP class to help you use it.
CutyCapt seems to be a very good option for you. Its very easy to integrate also.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.