I made my own, it was slow but easy work.
1st make the "T" shapes. I started with a 3/4" by 2" by 12" long piece of hard maple and cut a 2" long "tongue" on one end. Then I slit it into 4 pieces, just at the tongue end. Then I cross cut it so I had 4 T-shapes. (I can try to draw this if it is hard to understand). The reason I did this with a 12" long piece was to keep my hands away from the saw.
Now I had four tuners but they were rectangular - the part that needed to be round and tapered was actually 3/8" square and the "handle" part was a square, 3/4" by 3/4" by 3/8" thick. The rest is done with a small drum sander, files and sand paper.
First I made the shafts perfectly round and straight (not tapered) -0.308" in diameter. I got them accurate to +/- .002". This involved sitting in a chair with a file and a dial caliper and watching football and removing high spots. Use a towel to keep the sawdust in your lap and not on the floor.
Then I tapered them (I forget the exact dimensions, I have them at home, but I am on a business trip). A friend gave me the exact dimensions. Again, you sit in a chair with files and sandpaper and measure very often.
I drilled the headstock holes to the minimum diameter and then enlarged/tapered them with a reamer I made from one half of a pair of scissors. I separated the scissors and then ground the dull side until the scissors had the exact taper that I wanted. Be sure you do not grind the sharp side!
The reamer got noticeably duller as I reamed the four holes but it lasted well enough to make one ukulele.
The tuners work well if you play the uke every day. If it sits for a week or more it is a pain to retune. So if I plan to play it in public I make sure that I play it every day for 3-4 days beforehand.