Hi,
Though I am not located in UK, we can have teamviewer session to debug this issue. I did such debugging on several projects before. I have uno board but not maxim 7456 board. As this is standard SPI communication, there is no special or complexity about this communication. We need to debug serial reception, frame buffer population and then finally sending data to max card. With a remote session and guidance on visual feedback we can quickly solve this issue.
Thanks!