Regarding the trigger: Take a look at it then search the web (suppliers) for one that looks like it. Don't leave out Jewell.
Squared and worked most probably means that the action has been 'blue printed' which in turn means that:
Threads have been trued to be center of action,
Bolt has been trued to be on center line of bore,
Bolt has been faced to be squared with the bore,
Action face has been squared with line of bore.
Maybe a couple of other things also.
If all of this has been done it would make sense that some truing techniques were also applied to the barrel.
First thing I'd consider doing is a good cleaning and copper removal. Use a decent copper remover(Warthog 1134 - on the web, Wipe-Out - at any decent sporting goods store
, Montana X-treme Copper Killer - any 'really' decent sporting goods store.
Follow directions closely.
Then completely clean ever 15-20 rounds or so.
Should be good for about 1500 rounds or so....
Also get a decent cleaning rod guide. That would be a good idea.
Oh, and welcome aboard!!! It's a great place to pause and smell the roses.