Need pics for sure, but if it is not an SE car, no where near 20k. Not trying to hurt your feelings, but you can't go by any of the book values for real world pricing. Really nice, restored to original, or original, 403 cars sell for mid teens at most, unless it is an SE car. With no pics and by your description maybe 10k, really need to see it though. Could be less, if condition is worse than stated. I've seen some nice 400/4speed cars that only bring about 20k or so, and they usually bring about 4-5k more than 403 cars in the same condition.