HI Jake! My word, that's a challenge! Racked my brains but so far all I came up with was passionfruit which sounds unlikely, but who knows... Right size and shape for avocado but they are black and shiny. You did a heroic job sorting them all out! have you got any germjnated yet?

Hi yorks ,90% didnt germinate ,i had three distinct seedling that did,ime 99% sure now one is a kiwi fruit after
looking at hundreds of fruit leaves on google , lol.The other two ime not sure one looks like a tomato leaf ,and maybe the other a passion fruit (i have some large passion fruit plants) and have compared the leaves and they look similar.Thanks for your thoughts .

I didn't know what the leaves of passionfruit are like but I recently ate a fruit and the seeds looked the same...
Anyway you have a task that should keep you occupied for a while if they all germinate!