Thanks for the reply.
No, Bettinsoli is not in my book. Thus, my lack of information...
According to DU, this gun is unique in that it is one of only 850 made, and it is one of only two DU models ever offered that were not stamped anywhere with the manufacturer name. (The other model was made by Bettinsoli as well.)
I have also read from more than one source (and the DU rep confirmed) that the DU models are worth more than the non-DU models. Perhaps that's not true in the real world.
Yes, it has screw-in chokes -the gun includes 3
No barrel selector
20" barrel, I think