Need help Centering SMLE barrel (trigger guard issue?)

[browningautorifle]

I don't want any chance of the wood warping due to my fitting.

That's not what causes warping or twisting. Although Ontario's humid summers can be almost unbearable, they aren't sufficient to cause warping. Not like some of the member's here have experienced in their home areas.

When the wood was set up horribly, the gun shot 2MOA with undeveloped handloads

Doesn't sound like it was set up so badly...