Follow-up on Oki telephones:
Oki is the last name of the founder, it is not an abbreviation, so even though it appears in all-caps on the sets, it's also correct to spell it with only the first letter capitalized. This is similar to the case for some other large Japanese manufacturers with long histories.
History of the development of the Type 4 Automatic Telephone is here:
http://www.oki.com/en/130column/05.htmlIn brief, developed in 1948, became a national symbol of Japanese postwar recovery, components were produced cooperatively by six companies and complete sets were often assembled from more than one company's parts. Thus if you find a "mongrel" with parts from different manufacturers, it was most likely assembled that way to begin with.
Taiko was an Oki subsidiary that originally produced some components. Taiko also produced complete dials from at least the 1960s - 1980s, using a mechanism more closely resembling Western Electric (the flywheel governor and clutch mechanism for example). Taiko dials were also used by Bohnsack Equipment Company in New York in their well-known heavy duty type 1011 hand test sets.
The Type 4 telephone was mass produced from 1949 - 1963. I have a few examples of these, with parts variously stamped OKI, NTK, NYC, NEC, Taiko, and Iwasaki (these may have been the original six makers of these sets). A couple of components are dated as late as 1966, and it appears one of the sets has a 1969 date that I think may have been a reconditioning date since it's stamped in a different location on the label on the bottom. I also have one in light green from 1955, with all components made by Iwasaki, which company continues today as a producer of lights and lighting equipment.
Near as I can tell, there isn't a way to adjust the ringer on Type 4 to bring the rear armature of the clapper closer to the bell coils and thereby reduce the loudness of the bells (as can be done with AE ringers, most GPO ringers, and Dutch PTT ringers by all three Dutch manufacturers). So these will always be quite sufficiently loud to hear throughout the house. The dials on Type 4 are almost identical to AE dials except slightly larger, so all of the methods used to recondition and adjust AE dials apply to these as well. (Except, as Larry showed, the number label retainer is similar to Western Electric but with the tabs on the sides, so you won't need a tool or special technique to remove it.)
The little badges attached to the front can indicate either the manufacturer or the end user. I have a couple of black ones with the same circular logo as Larry's example, with an apparent stylized S in the center. Though the S could be an artifact of the logo design, and the actual symbol could be the two half-circles with bars at the end, similar to a modern "recycling" logo, perhaps representing Japan's national telecommunications company. The light green one has the Iwasaki name and logo in it, the logo appearing similar to a three-bladed propeller.
(My report of high sidetone was incorrect. One of my Type 4s came w/o a handset, so I added a British Ericsson (ETL) handset of the type imported into Canada, that uses a transmitter similar to the WE T1. That example has high sidetone. The all-Japanese ones with all-Japanese components have normal sidetone similar to a WE 302 or AE 41. The Type 600 as imported by Radio Shack does have ferociously high sidetone on Panasonic KXTDA series PBXs but is OK on direct CO lines.)
Type 4 was replaced by Type 600, which as I mentioned, bears a slight resemblance to a Kellogg 1000 or GPO 706 when seen from the rear.
Oki eventually transferred its entire production of Type 600 telephones to Taiko, while Oki went on to produce all pushbutton sets. The Japanese pushbutton sets with the later housing design use a very interesting ringer similar to a door chime but at ringing frequency rather than "ding-dong," which produces a wonderfully melodious ring.
The Type 600 was imported into the US by Radio Shack and sold in beige only, with the straight handset cord. These units were made by Toshiba, as you can see the Toshiba name inside the housing in front of the hookswitch plungers, and also in the receiver shell behind the receiver element. However other manufacturers produced Type 600 as well, and the various key telephone systems using Type 600 components (dials, handsets, etc.).
More on the Type 600 here:
http://www.oki.com/en/130column/10.htmlThe English language page of a Japanese telephone collector is here:
http://www.naonao.jp/tel_eng/html/tel/index.htmIf you click the tab for the Type 4, you'll see eight additional colors, and if you look closely, you'll see the various different little badges on the front of each one. It would be interesting if someone could figure out what all of those badges are, and what the mysterious logo is that looks like a recycling symbol or a stylized S in the middle.
There's an email link on this person's site, if any of the founders of this site want to invite them over here, it could be very mutually productive.
