Armalite M-15A2

The trigger feels kind of rough lately with creep. I cleaned the whole trigger assembly with brake cleaner, then oiled the parts that I thought are touching when the trigger is released. It is better but still much rougher than other stock triggers I have.

There is not much travel but I have to really squeeze it. Why is this happening? Has something wore out? Am I not lubricating properly?

Is this a candidate for "15 minute trigger job". I don't want something aftermarket like a target/competition trigger, just a slightly smoother trigger.

This is exactly why I use that method.

I want to start with the polishing part and if that still doesn't work, move onto the springs. How much of a difference do you think polishing the sear surface will make?

Secondly, where do I get the  "Fine compound (#7 rubbing compound or Kit Scratch Out plastic polish"?