Snakebite-
If you sent for your 1st deposit in March, 2nd deposit in May, and this is only June, and you are already getting anxious and calling about a chassis number, you need to relax and find a hobby to occupy your time.
You won't get a chassis number until a week or two before they actually start welding the frame. And I would trust Peter's estimate on when that will be. Besides, think of all the time you will have to figure out what color to paint it.