As the D of A thread is now closed I am posting this response from Hattons here:
Good Afternoon Ron,
Thank you for your email.
We have been set an allocated amount from Hornby for the R3819, of which all of our pre-orders are included. As such there should be no issue in us being able to fulfill your order.
I hope this helps, if you do have any more questions then please do not hesitate to ask.
Kind Regards
Colleen