Definitely not garden party.. Maybe First Prize ?

Have a look at Folklore too. A photo of bloom that’s further open could also help narrow down/confirm your variety. How does the bloom age? Do the petals roll back into points or does it maintain a more rounded shape, what colors are more prominent etc.

Here it is as it fades. I’m not sure whether the darker dots are from the flower dying off or whether they’re party of the rose. Thank you again for the information!