My Maxum 240SCR has had 2 cabin doors break in the last 2 yrs. The
first one I replaced with a stock door which was hard to find and
costs $500. I would like to make a new one The original is around
24x48 translucent bronze polycarbonate (as I understand it) and 3/8"
thick. What I am wondering is can I use white starboard in the same
thickness? Will it be strong enough? If I go thicker, the lock won't
fit properly (it sets on the top of the door and a cut-out).

I can probably find polycarbonate and cut that, but am afraid of
another breakage.