1. How far up the sides should I go with the 1708?
2. Is it Ok to fill the keel in the bow with epoxy putty then lay 1708 on top?
Careful with that cap sag. May want to support the hull sides.
The epoxy gets real slippery if you step in it - don't ask how I know that
You mention the original battery box - where is that again? Is it where the original baitwell was on these boats, below the sole where the "windows" may be?