Any weight-lifting enthusiasts here? I could use your help. [View all]

I'm trying to improve my chest presses in order to keep my pectorals in good shape. I was fortunate enough to inherit my father's physique, broad shoulders and a barrel chest. But I also inherited my male family members' tendency to run to fat pretty quickly if I don't exercise regularly.

Anyway, I do about seventy-five chest presses three or four times a week, using 35-lbs dumbbells. My upper pecs look very good., and have made me confident enough to start wearing tee-shirts again that, well, aren't tight, but fit well enough to show off my chest.

The thing is, my lower pecs aren't getting the workout they should, and are starting to look a little, well, dangly. (I'm fifty-six; gravity is going to cause some dangling; but I'm trying to stave off the inevitable.)

This is where I could use some expertise; What exercises could I do that will work out my lower pecs, and give them the definition of the uppers?