In case you don't know what the Dwarven Urgrosh looks like:
This is what I've ended up homebrewing:
Dwarven Urgrosh 50 gp 1d10 slashing/ 1d6 piercing 9 lbs Heavy, two-handed
One of the appeals of this weapon is that it is a double weapon. I thought about some different ways to handle it, taking a look at the notoriously unbalanced DnD wiki, and finally decided that the Dwarven Urgrosh can be used with the Polearm Master feat. Instead of the secondary attack doing 1d4 bludgeoning damage, it instead does 1d6 piercing damage. To balance the higher secondary damage, I decided that while this weapon was a polearm, it didn't have the reach property.
We'll see how well this all works out when the new game starts Sunday.