He is very pretty, but I don't think he is Lavender. Lavender is supposed to be all over the same even light gray color. He has dark hackles - maybe red? on the wings and a white chest. That sort of looks like Silver Partridge to me?
I don't have Lavender in Silkies, but I do have it in Ameraucanas. They are a very even color - all over.
If he came out of a Lavender breeding pen, maybe he is "split" for lavender and only carries one gene. He wouldn't show the color with only one - you need two to have Lavender. Lavenders can be bred to Black to produce splits which can then be bred together to get Lavenders.
Oh, and the color that was accepted in Silkies is not called Lavender - its called "Self Blue" even though the gene that makes it is called Lavender.. Just FYI.
Well shoot. Now I don't know what to put him with or just keep him as is. But I think he is very pretty. And he has a great temperament. Any ideas? I'm afraid his offspring won't be worth anything