I just wound up with a Mossberg 500 12 gauge with a busted out trigger group. The previous owner said that his buddy (obviously) tried to force it, and broke the front flanges on the housing that connect to the receiver.

My question; does anyone know where I can get that part or a stripped version of it for a decent price? I've removed all the components from the housing.

He also broke the screw that holds the ejector so need that as well.

Any help is appreciated. I'm not real sure where to look for a good price.

Check with Numrich's. http://www.gunpartscorp.com/
The website is a little strange to navigate, but you can either go to the schematics page, or search by the firearms manufacturer in the drop down menu, here:

https://www.gunpartscorp.com/Manufacturers/S.htm

Ebay actually has the trigger groups often

Try Mossberg directly the price might surprise you or they may repair it under warranty for free

Gunbroker as well.