Anybody who thinks it isn't worth gathering up treasure for Lei hasn't played through Resident Evil Village yet. Bucking the tradition that many other games carry forward, money does not become a negligible commodity due to the oversaturation of the currency. There flat-out isn't enough money in the game to buy and do everything.
So every bit of Lei counts. Many players will sell the head or the body of the Madalina Doll just to make a quick buck. But combining them makes the unit sell for many more Lei than the sum of the two parts. It makes economic sense to find them both and attach them before cashing out, it's just a matter of finding where they are.
Finding The Madalina Body
The Madalina Body is the easier of the two dolls as it doesn't require any keys, cranks, or wheels to gather up. Right in between East Old Town and West Old Town, there is a house with a treasure icon. However, the location of the Madalina Doll body is not in this home, but rather it is in the storage shed in the same yard, just to the south of this home.
Upon entering, follow the left-hand wall until finding a bunch of shelves. The doll's body will be here, on a cabinet in plain sight. Since Ethan has gone this far, might as well look the shed for bullets and other trinkets as well to save a trip for later.
Finding The Madalina Head
First thing's first, players will need the Well Wheel in East Old Town. It's in the yard opposite where the Madalina Doll body was located. However, this location is locked and needs the Iron insignia Key to get into. Like with the body, head into the shack and find the Well Wheel on a work table.
It should come as no surprise that Donna Beneviento, the doll lady, has the doll head near her location. Go to the Garden and move north when the path allows. Zoom in on the map and find the location of a well to use the Well Wheel on.
The Madalina Doll head will be fished up from the depths of the well. Grab it.
Open up Ethan's treasure menu, find either of the two parts, then select "Combine." This will complete the Madalina Doll.
Sell The Doll
Sentimental as a doll might be to players who explored and journeyed to get it put together, the Madalina Doll (now called Miss Madalina) has no other function than to be sold. Head back to the Duke at the Altar and sell it off.
That's an extra 20,000 Lei for Ethan's pockets, very close to a full level's worth of upgrades on a weapon, even at the later stages of the game. Congratulations on this new windfall of cash, spend it wisely!