If the pic of the rear sight indicates how far left you had to set it to achieve desired zero, and the gun shoots and functions correctly and to your liking, I wouldn't change a thing; that rear blade isn't very far left at all...

Otherwise, is a qualified revolversmith near you to have a look and make a suggestion? It seems a gentle "touch" a few degrees over in the proper equipment might correct, but you're right, if the barrel has to be pulled I'd guess the full treatment will be required.

The latter might be worth it if, say, you already have excessive barrel-cylinder gap, but otherwise I'd suggest avoiding "the works" and living with the slight cant if everything else is in order.

Again, I've seen the rear sight blade torqued a lot farther over to get zero on otherwise good revolvers.

__________________
Pickpocket