I have been tracking the prewar Terriers for about four years now, and this is only the 43rd specimen that I have learned about (maybe only 41, as I never got the serial numbers of two of them). They just aren't seen that often.
May I ask confirmation that the three digits in the middle of the serial number are 698? Deep-stamped serial numbers can be hard to read in photos. The same number should appear on the rear face of the cylinder and underside barrel flat.
I now believe that fewer than a thousand of this model were made, and maybe no more than 800. Aggregate postwar Terrier production (both transitional and redesigned varieties) is quite a bit higher. In top condition the prewar Terriers can sell for more than $2000. Even a well-used specimen like this one would bring more than its shooter value from a collector of rarely seen models. I don't know that anyone would spend more than $1000 for this one, but I bet several collectors and would-be owners might offer into the high hundreds for it.
Welcome to the forum. Nice way to make an entry!