Garage Door weather stripping replacement -- single groove
Yeah, I had that type of bottom on one of my other garage doors. The big center slot was meant for a compression fit seal that I couldn't find a replacement for.

I ended up filling that slot with this being modified. I cut the 2 tracks free, stacked them &amp; screwed them into the top of the big slot to then put in the Clopay type single T-end bulb. A pain to setup, but totally worth it for the ease of replacement twice before I moved out of the house.

However, your old seal's design is fine &amp; just needs to be screwed-in to the door's face every 3-feet to be fully secure &amp; still easy to replace. Something like this is what you'd be doing with aluminum or stainless steel screws through the shoulder that wraps up the door.