The turning piece of metal behind the lever is to hold the lever closed. Looks like the end of the lever was cut down.
The hole on the left side receiver belongs there to help put rifle back together again.
The piece sticking out of the tang behind the hammer is?? never saw before. Take it apart you'll know.
On bottom tang, one is screw to turn put pressure on the hammer spring, the furthur on end is to hold stock in place with longer top tang screw.
Dont go back to the gunsmith that didnt know Winchester.
Go to www.marauders.com
, open look at Win 73 exploded, enjoy.