Remington Pump Model 121

What would this one be worth? I saw it for sale today and am thinking about buying. It was made in 1936(the first year of production)Code EE. The serial number is 599. Condition is good, it fires, ejects and shoots good. The negatives include 2 holes drilled and tapped on the left side of the receiver for a scope mount I assume, and the rear sight is not original. I was thinking of offering $175. Is this too high, low, or about right? The wood is about 90% and bluing about 70%. Thanks for any comments or information.

"Let him step to the music he hears, however measured or far away." Thoreau