I heard the previous owner was curious why I changed the drive chain on the bike.  So, here are a couple photos of the worn drive sprocket.  It is actually a little difficult to see, but the points on the teeth should be closer to triangles than saw-teeth (see figure 16 below).  They are all flagged one way.  It might have been fine. but it was making a lot of noise and I wanted to replace it.  Also, you can see from the photos in the previous post that the old chain was very rusted.  I had a hard time flexing it once it was off the bike.

15 tooth drive sprocket, Front

15 tooth drive sprocket, Back (towards transmission)

Figure 16 from the Clymer Manual