I have a Department of Planning brochure from 1969 (they were giving them away when I got one in 1974) that shows the plan the Board of Estimate approved by that year. The plan is a little different from the version the previous year.
1. Instead of extending the Nostrand Avenue subway along Flatbush Ave., the line is extended along Nostrand itself to about Avenue W in Sheepshead Bay. There is also a Utica Avenue subway from Eastern Parkway to Avenue U/Kings Plaza.
2. Instead of an Elmhurst-Fresh Meadows line, there is a branch beyond 71st-Continental under Jewel Avenue to about Kissena Blvd. (I assume it would have used the existing yard portal at the south end of Flushing Meadows Park.)
3. There is no mention of extending beyond New Lots Avenue. Instead, the "L" would run along the Bay Ridge Branch from Broadway Junction to East Flatbush.