I want to confirm my uploaded manifest and the office-id it contains, but when I've signed in to seller dashboard it only gives me the option to delete it. Is there any way where I can see the contents of my current manifest?
You can download your manifest from Mcirosoft AppSource via this URL
https://store.office.com/app/download?assetid=WAXXXXXXXXX&cmu=en-US
Replace WAXXXXXXXXX with the asset ID of your add-in (visibile in the AppSource URL if you don't know it) and en-US with your add-in default language if different.