Mike, It is actually a closed car dash. Note the hole for the windshield crank knob. The upper roll in this dash could be viewed as part of the cowl on a 35-36 roadster or phaeton if you've never compared them to each other.
KiWinUS dash is late (after May) 36 closed car with mahogany grain. Late Deluxe 36 closed cars had separate water fall and walnut grain. See petehoovie
The '37 deluxe vertical trim strips between the gauges and the speedometer and those on the glove box door are chrome-plated zinc die castings. Those on the ash tray face and radio block-off insert are raised areas in the stampings which were chrome plated before the surrounding wood grain was applied.
A friend of mine might have the waterfall you're looking for. I saw it a few years ago and as I recall it was very nice.He also has a like new looking speedometer. I'm pretty sure they're '36 as he once had a '36 3 window. It would be worth a phone call. His name is Ken and his number is 707-443-9972.