I think ring dips are also very good, especially when you focus on the stretch at the bottom.
How do slight decline bench presses feel to you? Still mostly triceps, or do you feel them more in the chest?
You could try doing some chest activation before pressing, for example a Sven press - you stand up, grab two 2.5 or 5kg plates, squeeze them together and press horizontally in front of you. There's a video of CT showing them at the first Indigo Boot Camp somewhere.
I'm also wondering if maybe doing the opposite of what powerlifters do could help. Normally you would try to tear the bar apart, leading to a greater tricep activation. But if you try to squeeze the bar in, your chest should activate more. I've never done it on a regular bench, but I've had good results with it on scrape the rack bench.