Lance

In 1991, the MTA was considering a reduction in service along Central Park West. Their proposal included eliminating the C entirely and replacing it with a full-local version of the A. It also called for rerouting the Q from its then-current terminus at 21 St-Queensbridge to 207 Street, running express along Central Park West, as well as the elimination of rush-hour Concourse express service and direct local service to 6th Avenue.
 
Following community opposition to the original proposal, mainly relating to the loss of the legendary A service in Upper Manhattan oddly enough, the MTA revised their original proposal. In this one, A service to/from 207 St was retained, but ran to Brighton Beach via 6th Avenue, as opposed to Lefferts Blvd and the Rockaways. With the A running along the Brighton line, the Q would've been eliminated and the then-current C service would've been kept and extended to 207 St during the times the A would not have been running.
 
This map shows daytime and evening service.

In 1991, the MTA was considering a reduction in service along Central Park West. Their proposal included eliminating the C entirely and replacing it with a full-local version of the A. It also called for rerouting the Q from its then-current terminus at 21 St-Queensbridge to 207 Street, running express along Central Park West, as well as the elimination of rush-hour Concourse express service and direct local service to 6th Avenue. This map shows basic daytime and evening service based on this proposal.

NYC Subway Line Maps, based on the older transit maps from the MTA in the '80s and early '90s, updated to reflect current service.