The S&W Model 1000 auto and the Model 3000 pump gun were made for S&W by Howa of Japan.
These were fairly close copies of the Remington Model 1100 and Model 870 shotguns, and the Model 3000 is close enough that the 870 owner's manual can be used for disassembly.
S&W sold the guns from 1972 to 1984.
After dropping the guns, Mossberg picked them up and sold them for about one year.
After Mossberg dropped them, Howa imported them under their own name briefly before discontinuing the guns.
Gun Parts Corporation bought all of S&W and Mossberg's parts and sell spare parts, including a few police accessories for them.
These were very good guns, and for a time had a "cult" following among some individual police officers.
The guns were dropped for lack of sales, due to the fact that they just didn't have anything to offer over Remington.
A Model 3000 in 95% condition would be worth "about" $300, so $175 is a STEAL.