Stuck Cog

I'd like to keep the Phil Hub, Cog's & Lock ring's intact if possible....

You'll need,

1 lockring spanner
2 x chainwhips
some old spokes
an old rim

Hold one of the cogs in one of the chainwhips and use the lockring spanner to remove the lockring on the opposite side.

Use the other chainwhip to remove the cog from the side that you've just removed the lockring from.

Build the wheel into the rim using the now exposed flange, you probably don't need to properly cross spokes and stuff, you just need to be able to use the rim to hold the hub.

Now remove the lockring and cog from the other side of the hub, dismantle from the rim and you have everything separate.

You could probably get away with building the hub into a new rim with new spokes and then just building the other half of the wheel once you remove the 2nd cog/lockring but because you'll have laced one side of the hub and be working on the other side, it will probably twist around and stuff and may damage the rim/spokes.