All I can seem to find on the net is that I need to email Andy Uttley, but I can't find an email address.
The one listed here is correct:
AU06But what do I need to email? Is it just the control points, then the start date prior to riding?
A list of control towns (where you'll get proof-of-passage), in order to agree the controls and check the distance. The DIY organiser doesn't care about the route you'll take, only the total shortest (reasonable) distance between controls.
When that's agreed you print out, fill in and sign an entry form (blank forms on the AUK website) including the agreed controls, date of your proposed ride, etc and send it to the DIY organiser. The 2 quid entry fee will get you a Brevet card as long as you remember to include an SAE.
You then do the ride collecting the proof-of-passage (including one at the start). Info control answers from other rides aren't acceptable, you'll need something with time, date and location. Fill in the brevet card appropriately, sign it, attach the proofs-of-passage (photocopy it all if you're paranoid) and submit to the DIY organiser with another SAE.
If you post your proposed control towns on here then a few of us can check for you, knowing how the DIY organisers do it themselves. That'll save them some work.
Why am I seeming to make this look so complicated?
Because it is quite complicated, and you've not done one before, and not many people do them. I seem to remember a stat along the lines of fewer than 200 individuals did DIY rides last year.