I’m also trying to achieve this…
I did exactly what you said.
I made a copy of the project page, renamed it Project Board and placed it in my themes directory.
But when I publish the page I get this error:
Parse error: syntax error, unexpected '<' in /home/sickwebm/public_html/wp-content/themes/gridportfolio/project-board-template.php on line 456
what am I doing wrong?