This manual is available for downloading as a pdf. It consists of nineteen pages, including the front cover, and is a three-megabyte high-resolution document formatted for 8½ by 11-inch printing. This is RCA Manual No. IB-24428-1. Scroll down to see two more pages, including the title page, which lists the Master Index numbers for the turntables covered.
The RCA Type 70-D Transcription Turntable.
An RCA catalog page, courtesy of Dan Slentz.
An RCA 76-B2 Audio Console, RCA BCS-2A Switching System,
RCA 70-D Transcription Turntable. Photo courtesy of Chuck Pharis