The main pictures I have used for referance come from the following books:
Ford GT Then and Now - Adrian Streather - P206 shows a picture of 1012 at Daytona 1966 - this is before the rear deck snorkels were used and shows ducting from side intake (bottom 1/3rd of top intake) moulded into rear clip coming to a downward facing pipe on inside of rear wheel arch.
Ford GT40 The Legend Lives On - John Allen - P76 shows 1031 at 1966 Le Mans and shows how duct from rear deck snorkel connects into duct from side intake.
The Ford that beat Ferrari - Gordon Jones/John Allen - P130 shows 1012 in k11B form still with Y piece although duct to snorkels is disconnected as Shelby had removed from Mk11B at this time (although still fitted to H&M cars). - P113 has picture of 1031 in which you can just make out ducts.
P93 and P104 hve good pics of foam topped connector duct that leads to brakes.
1015 - Classic Le Mans 2006 Ford GT40 Mk II - Ultimatecarpage.com - Images, Specifications and Information
1016 - Classic Le Mans 2006 Ford GT40 Mk II - Ultimatecarpage.com - Images, Specifications and Information
1015 - 1966 Le Mans - you can just see rear clip duct Ford GT40 Mark II - Supercars.net
Also there are a fair few oics scattered around on various forums showing how SPF MK11 clip is formed.