Leman Russ's Primarch model was revealed at Warhammer Fest just recently. Now we have the second book for the Primarch Series from the Black Library
July 17th is Forgeworld Open Day, so its logical to expect the Primarch to be done by then, and available there. When will the model be for sale elsewhere? Well the guess right now is that it will be timed somewhere with the Black Library Primarch series books, which was just announced as coming in October. Perhaps we will get a second book for Warzone Fenris as well.
Here is what is being said, and the latest from the Black Library
via the Black Library