[Pursuivant]

I'd start with the stats for a TL0 Small Round Mace, since you're losing mass in favor of having a wider, narrower head. The video presenter gives the mass of one stone head as ~.75 lbs., so add about 1 lb. for a 2.5-3' long haft. That gives it a mass of 2 lbs., so base the rest of the stats on a Hatchet.

The head's shape gives slightly better initial penetration vs. DR, but ultimate penetration depth is limited by its width. For stone weapons, the disc shape makes it slightly less durable. For metal weapons, the weak point becomes the shaft directly below the head and it becomes more efficient to turn the head 90 degrees and turn it into an axe. Its design prevents it from being an effective thrown weapon.

It's clearly a lethal head-smasher, probably more so than a normal round mace, but no more effective than a TL3 flanged or spiked mace would be, and with less efficient performance vs. rigid armor. The flange on the end is just wide enough that it can be used to hook.

Notional statistics:

TL0, Small Disc Mace, Dmg: sw cr, Reach 1, Parry: 0U, $15, Wgt: 2.5 lbs., ST 8

Notes: Can't be thrown. Can Hook. Normally made of stone.

Optionally, does +1 damage vs. flexible DR including skull DR, but only to punch through DR. Might need to roll for breakage if it strikes rigid DR it can't penetrate.

This fits into the gap for Ace/Mace crushing weapons below the Small Round Mace entry.

Expanding the idea:

TL0, Disc Mace, Dmg: sw+1 cr, Reach 1, Parry: 0U, $25, Wgt: 3.5, ST: 10

Can be used with Ace/Mace or Two-Handed Axe/Mace skill. Increase damage by +1 and reduce ST to 9T.

TL0, Heavy Disc Mace, Dmg: sw+2 cr. Reach 1,2, Parry: 0U, $20, Wgt: 4.5 ST: 11T.

Uses Two-Handed Axe/Mace skill.

These all fit into the niche between Round Maces and War Clubs.

As for your second question, carrying unbalanced melee weapons is a bit of a hassle, especially if the heavy end is allowed to swing.

For 1-handed weapons, the simplest method of carrying is to stick the weapon in your belt.

The most comfortable form of long-term carrying is a belt loop or belt sheath like those used to carry folding shovels, with the head of the weapon next to the belt so it doesn't swing. Put a leather bag or purpose-made rigid leather cover over the head of sharp weapon for safety.

Stuffing the weapon into your belt or carrying it in a typical sheath prevents Fast-Draw, however, and requires several seconds of Readying. A fantasy or high-tech breakaway rig would allow Fast-Draw. It might cost 2-3 times the cost of an ordinary weapon sheath.

Small maces, like trench maces, were just attached to the user's hand by a lanyard or allowed to swing from the pommel of a war saddle. In the latter case, the the horse's tack and/or armor protected it from injury. WW1 trench raiders might carry the mace in their off hand, with a pistol in their dominant hand.

Big maces, in so much as they ever existed historically, have to be carried like 2-handed axes.