pump shaft

I have a question. We just submitted a motor for warranty and it’s being shipped. We wanted to put a new shaft on as recommended. I’m unsure of which one. I tried to reference our model # to what you have online and I’m not seeing a match.

I have two sets of numbers: SP261OX15

21121103005408023

Can you tell which one I need from these two sets of numbers?

Thanks,

Stephanie