This looks to be a very old style handle, but the design is very similar to our 40-049. I think this may be what you want, but review its dimensions and see what you think.
We don't sell retainer strips, unfortunately. The problem with these is that every manufacturer makes their own style for each door, and then they'll change that design from year to year. It makes it hard for companies like us to keep up. One thing you can try that I know works is to cut the existing strip into small, equal-sized clips, maybe a couple inches each. Then you just distribute them around the door evenly. This is how we did it back in the day and it still works now.
Lastly, looking at the rubber sweep, I'm not sure what kind of size you need. We have a couple that you can consider to start out: our 40-209, 58-162, or maybe our 40-207. Review the dimensions in each case to see if any of these will work for your door.