Hi Kim There are good photos (Reiner Richter) of Polistes erythrinus on ALA: https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:409bd0dc-71fd-4259-ba43-4b7dde4fca95#gallery
Polistes erythrinus has a more distinct separation of black and red colouration on the abdomen with an entirely black first gastaral band (which this one doesn’t have). Polistes erythrinus also has a black supra-clypeal plate which would be difficult to confirm from this image.