Lew Hodgett wrote:
My guess is that it will cost me at least $2,000 for materials and at
least a year's time.


My guess is that either you work very inefficiently, or else
you're sniffing too much resin.

For $2K and a couple months labor, one could completely
remove the deck, use it as tooling, mold a complete new one,
and install it.

You got this right: sanding materials & tools will both cost
a lot.

DSK