Ive built some over the years, the first 2-3 looked ok but had problems the local Inupiat quickly pointed out, some the stuff Ive learned the hard way and will pass on as I learned.
The Ulu's edge is chisel edged like a wood chisel or wood planer blade, the main purpose of the knife is sliceing and is done in a sawing/slashing manner(more control of the cutting edge), as a woman skins she uses sweeping gracefull arc's a skinning knife cant really copy.
The blades of working Ulu's are useally as thin as one can get (ease of sliceing and weight), Ive seen one's dug up with bean can lids for blades,
The handle is fit to the person, so if your left or right handed the handle is offset a bit to fill the curled fingers of the grasping hand, the short leg the blade is closest the body the bevel is up (sun face) twards your belly, handles are shaped for comfort and control while wielding a bloody knife or with greasy hands when cutting seal and whale.
Copper or brass rivet heads are formed by burnisheding in place insted of impact riveted, now days pins simply epoxied instead of riveting.
Never imerse a Ulu in water they are always wiped clean like a cast iron skillet,
Ulu are rarely used for cleaver like chopping (due to light weight) the single edge blade can skew and you could get injured instead the blade is pressed down on what your trying to cut and you use your body weight to force the blade through and since its cross section is slim it useally glides right through.
Ther is the Ulu factory in Anchorage Ak, ther products are a hazy copy of the real thing kinda like one them chinese made leatherman copys of the real deal.
Ive lived on the NW arctic coast of alaska since 1989