Need to identify if this is the seal or another part

Looks like you need new glazing. I can't tell what you have from these photos, though. In order to assist you, I will need you to remove an undamaged sample and show me a clear picture of the end profile. The video below will show you what I mean.

I have to stress that we have to see an undamaged sample. I know that yours is likely very brittle so this will be easier said than done, but please try your best. If it's too broken up then we won't be able to help you.