I've thought about that too, as I have a love of the PNW and was at the Columbia River last week before returning to So Cal.
There are no Columbia Rediviva kits, but you can make one from a Bounty kit, either the Revell or Airfix versions. The Revell is smaller but more user freindly for this conversion.
Columbia Rediviva was roughly similar to the Bounty - another late 18th century merchant ship - in terns of size, form and weight.
Columbia Rediviva had no quarter badges, according to paintings of the ship made during her voyage, and was painted black and yellow ochre. The lower hull was whited up to the lower wale. The interior deck color is possibly dark green, based on the dark appearance of a deck structure in the watercolors, which is clearly not red.
The stern panel extended out of the hull on either side and was decorated with carved wooden swags above the windows (5 windows, the center one possibly false). At one point boats hung from the side of the ship at the stern, at other times, not. The ship's boats are white with black and yellow ochre rails, and black transoms.
The figurehead is polychromed and represents a lady in a blue reddingote (a type of overdress stylish in the 1780s) with a light blue petticoat, a white stomacher and a large black hat. Her right arm is extended forward. The head rails are all black, as is the stem.
There is a deck structure aft of the mainmast where an extra capstan goes on the Bounty. It covers an entry ladder and has an arched roof with planking on the side.
I actually went out and started one, using an Airfix 1:87 Bounty. It needs a lot of work and I have infinite gratitude to John Tilley for his comments on this kit for guidance.
The Revell would be much simpler to convert in a representitive Columbia Rediviva, as the quarter badges are separate peices and there is no copper sheathing on the underwater hull, which helps to represent Columbia rediviva's traditional whited hull.
Jim