Beijing 北京 SB-5

Model : Beijing 北京 SB-5
Manufacturer : Beijing Watch Factory 北京手表厂
Year of Production: in between 1967-1974
Case Diameter : 
Weight w/o strap: g 
Movement Model : SB-5 (17 jewels) 
Type : Hand Wind 

1967 saw the introduction of the SB-5, a new design of similar layout to its predecessor [BS-2], but simpler to produce. The escapement was upgraded from 18,000 to 21,600 beats per hour. SB-5 watches gained the 'Beijing' label in addition to the Tiananmen logo of the previous watches [BS-1 and BS-2]. 'Beijing' brand was superseded by 'Shuangling' with the introduction of the ZB-1 watch. 
The above is the quote from Wiki (link here) and you can see how old the watch is. Also noted that Beijing Watch Factory 北京手表厂 turned to standard movement in 1974. Between 1967 and 1974,  1,617,568 pieces were produced and, of course, this was one of them.

On the dial there are words "17 Zuan" (17 Jewels), "中国 北京”(China Beijing), “Zhongguo Beijing"(pinyin of China Beijing) and "SB-5". The design is similar to Beijing 北京 SZB-1. The words on the caseback are "北京“, ”SB-5"  and "Beijing".

More shots are here:

The Portrait;
The Dial;
The Crown;
The Movement;
The Movement and the Caseback;

My other watches from Beijing Watch Factory are here:

Beijing 北京 SZB-1
Beijing 北京 Shuangling 双菱 20J