Here's the R42 location listing as of January 28, 2020, AM:
East New York: 4792/93, 4804/05, 4808/09, 4810/11, 4814/15 (X), 4822/23, 4828/29, 4832/33 (X), 4836/37 (X)=18. (X)=Previously Retired.
Fresh Pond: 4800/01, 4812/13, 4820/21, 4834/35=8.
Pitkin: 4788/89, 4794/95, 4802/03, 4838/39=8.
Coney Island: 4798/99, 4816/17, 4824/25, 4830/31=8.
207 Street: 4790/91, 4796/97, 4806/07, 4826/27=8.
(50 Total.)