I bought my first t-handled Phillips screwdrivers from the Honda tool catalog in 1975. I got all three, #1 Phillips, #2, and #3. I had to replace the #2 several times before I stopped trying to loosen SOHC speedo drive screws with it (which systematically made it break) and subsequently also changed my technique. These Phillips screwdrivers were my mainstays for many years while working in shops, and still today I have the #3 one. It is the *only* tool I ever used on case screws. It's that good.
My t-handled Honda factory Phillips were made by Kowa Seiki, a little-known Japanese tools supplier founded in 1949 and reorganized in 1952 with an office in the same city as Honda's Japanese headquarters. They were the maker of all of Honda's special tools, as well as Kawasaki's, Yamaha's, Suzuki's, and Mitsubishi's during the 1960s and 1970s. Rather ironic, considering how cheesy the stamped-out Honda underseat toolkit tools were during this same time, since Kowa made all of those also. You can still find many of these with the Kowa name on them, some of them with the Honda name, all over, including on eBay. But the Honda catalog stuff was just brilliant! Exotic, in fact. Elegantly simple and effective slide hammers, holders, valve guide drivers and reamers, cam chain riveters (the first ever available), and the world's absolute best clamshell type piston ring compressors (I own a complete set).
In August of 1980, Kowa established their first U.S. subsidiary and distribution center, in Lawndale, California, a suburb of Los Angeles. Despite this, Kowa Seiki's fortunes seemed to soon change. Yamaha switched to an American company, Kent-Moore, and Honda unprecedentedly and inexplicably also switched to an American supplier, GNK. Oddly, at this same time, Honda Australia, Honda UK, and Mazda's headquarters in Germany, picked up Kowa as their official supplier. A call to Kowa's Lawndale office in 1983 resulted in permission to make a retail visit to the L.A. warehouse with a half dozen friends (HSTA members, actually) and purchase direct several sets of t-handled wrenches and screwdrivers. The wrenches came in a kit, as did also the screwdrivers, in their own three-piece kit. Nice stuff. Still have those 8mm, 10mm, 12mm, 14mm, and 17mm t-handles. Superlative quality.
During the early years of the new millennium, Kowa U.S. finally got online, and sometime later Snap-On bought them and for all appearances completely absorbed the distributorship. The U.S. website is shut down, and the street address has changed several times, first to Torrance, then Rancho Domingas, then Cerritos, and presently is unknown. The Japanese parent company may still be in business, but it's hard to tell. Their Japanese website has not been updated since 2009.
U.S. control cable and hand tool supplier Motion Pro in about 1990 began selling their own version of t-handled Phillips, not nickel plated but good quality, and continued marketing these until late last year (2012) when they discontinued them. The sets for sale today on many websites (not Motion Pro's website) are in fact Motion Pro tools. Beware that orders to the websites will not be fulfilled if their companies do not in fact have the tools in stock, as they are gone. I spoke with Motion Pro's online sales manager on March 4, 2013 and confirmed this. They are no more. This despite their 2013 catalog listing all sorts of combinations of t-handled tools, including some screwdrivers.
The 2009 Kowa Seiki online catalog is geared toward supplying Japanese market repair shops, car and motorcycle, with lifts, wheel alignment equipment, air compressors, EGAs, and other heavy shop tools plus hand and diagnostic equipment. Very like Honda's tool catalog of the 1960s and 1970s, these hand tools are some of the best in the industry. The catalog however is in Flash, so can't be downloaded. Included in this catalog are the famous and historical t-handled screwdrivers, part numbers KL-1694, KL-1695, and KL-1696 for the #1, #2, and #3 Phillips sizes, respectfully. Gems, absolute gems. But can one get them, short of going to Japan?
When I first bought my nickel-plated, superbly machined Kowa tools in the 1970s, all of Honda's tools were made by Kowa. These were highly specialized tools with Honda part numbers stamped into them and available only from Honda, and for a short while also Yamaha. I still have quite a few of them, as I was a Honda fanatic in the early days. Near as can be determined, Kawasaki and Mazda were the last to use Kowa as an OEM supplier. Kawasaki even today sells Kowa's diamond lap valve seat tools. I have some of these too, and understand they are in limited supply. No better hand type valve seat tools exists though. Pity. Seems the good stuff just doesn't last in a world increasingly geared toward disposability.
Update 2015: T-Handles are again available, and now you a number of choices. Among them are Motion Pro, whose t-handles are available from Amazon. Also, it seems Pro Circuit is importing the original high quality Kowa set in from Kowa Seiki Japan. This is ghe same set I own. Finally some Taiwanese companies have started duplicating the Kowa set, and these tools appear to be good quality for a good price. You can find these latter examples on my website.