Jubilee X Black will produce (in theory) all Black chicks recessively carrying the Mottling (and a few other) genes.
You can cross the pullets back to their fathers to get birds that will be Mottled and some that might even look a bit like Jubilees. The resulting Mottled birds might show some read leakage due to the Mahogany genes that the Jubilees have. If you want to breed for a solid Black Mottled bird you would want to select against any with leakage.
The Blacks will be carrying the same genes the Jubilees have they will just be hidden inside, it will take a few generations of breeding back to their sires to coax the right genes out and produce a true Jubilee colored bird again.
This is a great way to outcross and improve your gene pool while working on bettering different qualities in your line. It will take a few generations to get back to where you started but it will be well worth it.
Don't be afraid to outcross to Blue too... keep that Blue gene in the birds and eventually you'll have Blue Jubilees! The same can be said for Chocolate too, Jubilee X Chocolate with the right back breeding will eventually produce a Chocolate Jubilee colored bird.