Try this...I bet that at some point the barrel was removed from the stock and the magazine box (D-27 in the Ruger Operator's Manuel) was put in wrong...
Make sure the taper on the box goes to the front...While you are at it, make sure the Magazine Spring (D-33) is installed properly...The "hump" should be on the left, so the last 5th cartridge is on the right of the magazine...

I prefer the older "tang" safety Rugers to the newer 3 position safety...The trigger on the tang safetys can be adjusted and I prefer the tang type safety. Its easy, quiet and fast...