Pepakura is a good start for a base. You will need to fiberglass and smooth the edges smooth. Seen a few folks do these. Long Process not to be rushed.
Lucious Talvloinne TR-4126 (Stephen Davenport)
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So long as it looks like the right shape, color, and gloss I don't think if it matters if it were made of plastic, fiberglass, paper, or grass. So long as it looks good I think it's great.
Update
Been slowly working on this but this is where I'm at I'm having my doubts about it fitting my large head but if all else I'll finish for a display.