Iron,
I looked ar your other post and was surprised that none of the smiths on this forum answered your question.
Most triggers can be improved by polishing and internal modification.
Polishing and stoning removes small amounts of material which could upset critical contact areas and may also effect hardness of the trigger components, this should considered before any work is undertaken.
Any smith worth his sort should be able to help you here, advising you of what is involved, he may not want to do it, preferring to install an aftermarket trigger.
I would check out the cost and work involved, you may find that the aftermarket trigger is more economical.
Ian.
"I meant to shoot the pike but the duck got in the way"
PS. Cooper firearms are in my eye, extremely handsome rifles.