Yay for getting a girl.
Now, for Fluffy's handsome boy you have time. I would start now knowing for sure he is a boy. List him expecting it to take time to place. I would advertise him as a Polkie, silkie x polish cross. I would also throw in pictures of dear departed Floyd to show a "example" of what he may end up looking like as he grows. Obviously different color, but possibly same body type. Add in pictures of Mr. P and Fluffy in the listing. He may surprise you and have interest right away. If he does, you have to decide if you want them to wait a few weeks until he is weaned or if you want to place him right away. If he is 3ish weeks old, I would be inclined to go ahead and place if they are set up to finish brooding him out, but that is your decision. Another thing to ponder on while he is listed if it takes time. You may find with him being the only boy Mr P and the girls may be more receptive to a young roo. He could be the 2nd in command that Mr. P could use. Time will tell.
He might be a kinder, gentler roo, given he is half Mr. P And, honestly, Mr. P DOES need help with all those ladies!!!
I have time to see how he behaves.
And while I am sad to not have a Marty baby, having a Curly frizzle baby girl is really eggciting.