not the one you responded to but:
The HD version of the image simply does not exist online. The only possibility to get the image is to contact the artist directly and ask for the full HD image.
This thread has gone on for a month and it has to stop; even I tried to help, spending the day looking for it. It's not online.
OP has already received suggestions, advice, etc on how to go about it but rather than acting on it, they simply want others to hand it to them. People have already done the work, reached a conclusion, and gave info; its OP's problem now and the solution is not continuing to bump this thread for others to do the same work and reach the same conclusion.
You can even see above the links to the company, the artist's websites, etc. as well as the advice and suggestions. No one is going to hand hold them for the rest.