Here is the schematic diagram for the Shure 526T desk microphone,
of that same era, that used a dynamic element microphone.http://bama.edebris.com/download/shure/526t-preamp/Shure%20526T%20Preamp.pdf
Altai likely used a readily available Japanese transistor (2SC).
Last address, now in Taiwan, as of 2009.
ALTAI COMPONENTS LTD.
Phone Number: 886-2-23250760
Fax Number: 886-2-27000818
Zip Code: 10683
13F-1, 26 Tun Hwa S. Rd., Sec. 2, Taipei
Taiwan, Republic Of Chinahttp://www.altaitwn.com.tw
Primary Export Products: Turntables, Record player and turntable parts, Loudspeakers,
Other loudspeakers, Amplifier sets, Audio equipment parts, Aerials and aerial reflectors,
Microphones and stands, Other line microphones and stands, Audio equipment parts,
Machinery and apparatus