Ok i went all the way down the rabbit hole… which i enjoy sometimes. There are at least two… Hollywood plums that i think folks are growing now. Hollywood and ‘fake Hollywood’/Spencer?
1)The round one- Sold by most nurseries.
2)The oval (egg shaped) one- Sold by Raintree and maybe others.
Im not sure if a pic of ‘Spencer Hollywood’ exists… but there are for sure pics and videos of round Hollywood plums… and oval egg shaped ones.
Arthur Lee Jacobson wrote a (the) book on these plums…

Authentic Hollywood plums are ‘round’.
In this forum there are round and oval Hollywood plum growers.
However im not sure there is anyone that grows them both and can compare.
Not saying that the oval ‘egg shaped’ one is ‘Spencer’… but according to the expert its not “Authentic Hollywood”.
Also while going down the hole… Hollywood on many nursery sites only need 300 or so chill hours… but it is also Z4 hardy. I found one grower growing them in Montana… so its a very diverse plum.
Also many nurseries say its self fertile… others say it needs a pollinator. Some nurseries say its a Euro/Japanese hybrid… and some say Stanley is a great pollinator and on and on and on with various sources listing various pollinators from Japanese to Euro.
I have no idea how CHAT could come up with an honest answer on any of this… as there are way too many ‘facts’ to interpret…
I did my best as a human.