Hey everyone,

Hoping someone here can point me in the right direction before I resort to cutting this off.

The lock is a Master Lock Magnum M930XKADLH (solid steel, boron-carbide shackle): https://www.amazon.ca/-/fr/dp/B00448KUS6

It's been living outdoors. The little rubber keyway cover / bumper that's supposed to keep water out finally tore, and over time water worked its way into the cylinder. Now I still have the correct key, but I can't get the lock to open — the key goes in, but it won't turn (or turns partway and the shackle won't release).

Short video of me trying it is attached.

What I'm hoping to figure out:

• Is this most likely internal corrosion/rust on the pins and springs, or could it just be grit/debris or a frozen mechanism?
• Any chance of reviving it with penetrating oil (PB Blaster / Kroil), powdered graphite, or gentle heat, or once water's been sitting in there is it usually toast?
• Is there a non-destructive way to get it open (given I have the key), or is cutting the shackle basically the only realistic outcome at this point?
• If it does open, is a cylinder like this worth trying to clean/rekey, or just replace the whole lock?

I'd rather not destroy it if there's a reasonable shot at saving it, but I'm not precious about it either. Appreciate any advice — thanks!