I originally bought a CYMA 040D. I thought it was to heavy and unwieldy and the FPS being to high for CQB. So I traded to a guy on SoCal Airsoft for an E1 M16 with an AGK MBK and some ACM EOTech 553. Bad trade, gun didn't even work and the holo sight wasn't that effective. So I traded back. What I got was a little off. It ooriginally had a RIS gas tube replacement, but he took it off and sold but he replaced it with some polymer lower RIS. Ok I guess, but I had asked him if he had ever took it apart. He said no. As soon as I got home and took a look at it, I noticed there were dents in the fire selector pin.
Now the fire selector pin is loose in that it only fires in semi and can go all the way up past the top shell.
Should I fix it and ask him to give me some money to fix it?
Or should I sell as is?
here are some pics:
Before:





After:





OH. AND THE MAG HE GAVE ME, DOESN'T EVEN FIT.
The project I want to do:


The stock is kinda wobbly, so I might want to change it.