Personally I would say there is no harm in getting it threaded for a can and cerakoted. It is your rifle now and it is a hunting rifle at the end of the day. Fundamentally it is a tool, not a display piece.
If it is cerakoted in black or midnight blue will still look relatively authentic and it will have far far better protection from corrosion via moisture than if you left it blued. I like to use my rifles and as far as I am concerned blued rifles perform poorly with regards to weather resistance in NZ conditions; it is simply too rugged and wet here for them. I am getting my old Tikka cerakoted for this exact reason. No matter what I do it still reacts badly to moisture and rusts. This is a problem when you cannot really fully disassemble a rifle in your tent to re-oil and re-grease it 100% properly on a multi-day hunt.
A can also makes the 270win a really pleasant rifle to shoot. I have found a quality suppressor takes the sharpness out of the recoil, allowing you to practice more and become a better shot without flinching. This is good for when you want to move on to bigger cartridges.
As far as chopping the barrel goes, the advantage of the 270win is that it moves quick and flat with a pill big enough to drop any game in NZ with a well-placed shot. Chopping that barrel will result in a drop in velocity which is the primary advantage of a 270win and is specifically what makes it a great 'do-it-all' cartridge for general hunting in NZ. If you do chop it and lose this velocity advantage you may as well just be running a 7mm08 or another 308 based cartridge which recoils less and is cheaper to feed.
At the end of the day it is your rifle, and you need to decide whether you are going to use it frequently or not. If not, then i would say try to pick up another stainless 270win that has already had work done rather than invest money to put your grandas rifle on par with something that is already available with less modification.
Just my 2 cents based upon my experiences with blued 270win rifles lol.
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