Re-barreled one with a Pac Nor stainless fluted 25" chambered to 6.5/06 AI.
Never in a million years would I consider upgrading the trigger on a T3. They really don't get any better in a big game rifle. I find the synthetic stock comfortable and keep in mind it is a Lite Weight. The reciever gives you 2 options for the style of mounts you can use. Tapped or dove tail.
The only things I could see people wanting to mod is the stock since it's the most personal feature of any rifle and maybe a muzzle break for the lite model with heavier calibres. Typicly you would not need to blue print these rifles. They have a reputation as being one of the most accurate rifles out of the box. The three in my gun safe live up to that reputation.
At this point there are no dropin/bolt in mods available that I know of. Maybe it's biggest downfall, or underlining the fact that people are happy with this affordable rifle right out of the box.