Its one of these , check serial to know the one. See the OZS stamp on yours , don't match your screen shot , could work in your favour depending on serial etc.
(specimen 1690) the placement of the 5 and the space between the 5 and OZS is also different - with twirls. specimen 1690 is different and some may say a more attractive and superior looking bar.
The top one id say no as its got no letter after the number. Bottom <500 looks very close but my serial No is even like one stamp that is individual. Id guess it could be different even with the person who made it on the day also.
Maybe someone hasn't submitted a picture and info. It's run by one person (or very few people), so updates can take time, particularly as AE often conducts some of their own research to corroborate claims made by contributors.
Nice pickup Bubble - same (a,b,c) genus I don't think its a mule could perhaps be a new sub-specie discovery a fine specimen, maybe get a ruling from Bigfella.