Howa of Japan made two shotguns for the US market, the Model 3000 pump, which was a close, but not exact copy of the Remington 870, and the Model 1000 which resembles the Remington 1100.
No parts will interchange with the Remington guns, except butt stocks may with fitting.
S&W marketed both guns under the S&W name from about 1972 to about 1984 before discontinuing them.
Mossberg picked up and sold both guns from 1986 to 1987 also under the Model 3000 and 1000 names, and somewhere in there Howa sold them under their name.
These were good quality guns, but simply didn't have anything special to set them apart from the Remington guns.
The Model 1000 has a problem with deterioration of the rubber "O" rings in the gas system, so these should be inspected often and replaced when needed.
The 3" 20 gauge model is worth a few dollars more. One in 95% original condition would be worth around $325.
You can buy parts from Gun Parts Corporation under both the S&W and Mossberg names, and from LSG.
http://www.gunpartscorp.com/
http://lsgmfg.com/