It would be nice if a complete Re & Re "plug & play" kit could be had, remove existing parts and install new, that way the OEM original parts could be put away or sold. In this way no machining or fettling required. Easy Peasy as they say somewhere. I'll start saving ...
It is pretty easy to do a "plug and play" because both the JE stem and the DD stem can be installed in their most basic iterations. If you want taper rollers and bearings in the links it gets complicated.
There is no handling advantage gained by using taper roller steering bearings. The cups and cones with balls are fine. I designed a taper roller conversion to use in the racer because the lower steering cone broke. This is unusual, but not surprising. The lower bearing pocket was damaged when the bike was purchased and when I found the damage I decided to cast up a new steering head and machine it for the taper rollers, which are 42 mm metric bearings.
But, if the old bits are working fine, the DD stem is a simple swap using all the original parts, including the eccentrics.
On the stem above, I installed the eccentric stops, the FF36 washer, and the FT124 cone, so the purchaser could simply install the stem on his stock bike as a direct replacement. I believe TT can do much the same with a slightly different design.
My local machine shop went out of business a few years ago and I have not made a new batch in years, but can occasionally get some from a far-away machine shop that does a nice job.
Congratulations to Vincent for doing such great work. The Speet brakes should work much better with this mod!
David