If you are sure a Release exists then you can add it.
The bare minimum needed to add it to the MB database is the Release title and an Artist.
The Artist either needs to either; be in the MusicBrainz database already, or, you can add the Artist at the same time as you add the Release.
I see you’ve added lots of Cover Art for the Bigman Vol. 6 Release.
Thanks. It looks good. The cover art tracklists are especially valuable I think. One day computers will be smart enough to read the data on them and check all the info we’ve added.
If you’ve got the time and interest you could also add the MB Disc ID for the Release and also the MB AcousticIDs for each track/Recording. You can use Picard to do this.
Adding the Disc_ID is fairly simple:
Adding the AcoustID seems more complex (I’ve only recently understood that this does not happen automatically, so lots of earlier Releases I’ve added do not have AcoustIDs for each track/Recording):
By adding these 2 powerful identifiers you help Picard recognise CDs and Recordings automatically - though still NOT with 100% reliability as different CDs and different Recording do occasionally have the same MB Disc ID or AcoustID.
Like IvanDobsky says, adding edit notes and annotations describing your source of knowledge about the Release is very helpful. All editors make some mistakes sometimes and having sources lets other editors correct those mistakes.
Keep up your good practice of asking questions about anything that isn’t clear.