Wow!! I wonder if I may speak without getting flamed for advertising.
The little cap on the top was originally designed for the pegbox of a Suzuki violin.. It adds nothing to the string post except another three mm of cap which was nice if someone wanted an inlay at the tip. The main shaft on 743af was 19mm. There is an 8.5 mm and a 9.5mm with that same length shaft. There is in the "not yet in production" stage another S(for short) 843A coming. Production of an internal part from a machinist shop here in the USA is the reason why we can give no definite time line. I do have an inventory of S8543 and S9543. With the model shown above the taper starts right at the base of the string post. The newer ones have the string post taper starting at the back of the thread, so it does not appear as MUCH larger than the old 8mm units. It really is tell the difference once they are installed.
There are other "look-alikes" sold by Music 123 and Musician's Friend. They re an off shore [China] product. They pay the shipping. Their guarantee to perform lasts for 45 days. They are called Perfection Planetary Pegs. The "Real Deal" says they will work when properly installed and not used as a cricket bat. Otherwise,they will work or be repaired or replaced. PEGHEDS have been on concert grade stringed instruments for about 16 years successfully. When someone pays more for a bow than anyone had paid for an ukulele, PEGHEDS have to be able to perform.
Cost is $55 a set of 2L and 2R and insured USPS delivery to the USA is 5.80 PayPal in USd . Foreign money through PayPal gets 4% as an addition charge to their standard of 4% fee over product and postage.
If the button is smoothed a bit with 600 - 800grit wet/dry in the pinch, and the whole button buffed with some compound (toothpaste is a very fine grit polish) on a cotton wheel, it looks as shiny as ebony, but with a smaller button. It costs less,also.
I am getting a prototype sample from Mr Herin this week. I think I shall start a new thread about it. Chrome shaft-ivoroid button.