Storm door bottom sweep
Thanks for posting. At first glance the end profile reminds me of the Larson 58-149. The dimensions are slightly different from what you show, as the illustration below shows; please double-check and let me know if you think this sweep might work for you. It comes in 37" lengths.
I pulled my sweep out thinking it was T shaped, but it appears to be two of the 58-149 placed back to back.
So, do I need to order two, or, does this item come as a set of two?
I've never heard of the 58-149 being installed back-to-back like you describe, but I suppose it's possible. It sounds like someone repaired your door at some point in the past and had to get creative.
The 58-149 is not sold in pairs, but rather in individual 37" lengths. If you wanted to try this out, you would need to buy a quantity of 2 (or however many you needed to make up the required lengths).