Some good experimentation documented on this thread:
https://rennlist.com/forums/924-931-944-951-968-forum/850961-diy-early-dashboard-restoration-megathread.html
I have to say that Mike O'Donnell did some cool car stuff while he was in college, including dash restoration on the balcony of his college digs.
And this company appears to make good materials:
https://www.polyvance.com/280Z-Dashboard-Repair/
John