Does anyone know whether angle of coverage refers to the complete angle or just from the lens centerline to the edge of the coverage area? Hope that makes sense.
Rodenstock has a 48* angle of view listed for their 890mm Ronar which would either translate to about a 15" circle or a 38" circle. Quite a big difference.
The angle of view (a) is given by the above equation, where ‘d’ is the dimension of the negative-format diagonal and ‘f’ is the focal length. 'a' is the complete angle of coverage.
Impossible to predict selling price, its a thin market. That said, and even though I bought a perfectly fine 900/10 Apo-Saphir for 101 Euro last fall, 900 mm process lenses typically bring more than $500, sometimes considerably more. But sometimes less. Look for completed auctions for Apo Ronars and Apo Nikkors on eBay. These days Google returns mainly irrelevant garbage.
Just put the thing up for sale on eBay and accept what you get.