So after a little more research I have changed and added some more details.
I realised I actually had 2 9C Uboats to build as early versions with the earliest being......
U-67. (Revell Kit #05166)
*This boat in 1940 had all the hallmarks of a typical 9C U-Boat in the early stages of the war - 10.5 cm & 3.7cm deck guns, small tower, small tower, wave breakers on the f'ward deck sides and one across the deck in front of the deck gun. These details will make this build a markedly different display to the later 9C builds, which is what this is all about.
U-509 (Revell Kit #05166)
* This boat will be similar to U-67 however over the time between, U-67 in 1940 and U509 in early 1943, the kit looses the wave breakers and gets the updated FuMO radar ARRAY across the tower front. The tower also gets a 'makeover' from the plain grey to multi-striped cammo bands.
U-441 (Revell Kit #05015 w/ Shapeways 3D Printed conning tower & details from kit #05163)
I have also swiched out the mid war 7C U-333 for another mid war Boat U-441.
U-441 was a very unique type 7C that was modified for a short period in the second half of 1943 to a Flak boat to provide escort to other Uboats. In late '43 it was converted back to a typical 7C but while it was a flak boat it looked completely different with 2 platforms with 20mm quad verlings and a 3.7 SKU30. One of the Quads was even mounted in front of the Conning Tower.
------------------------------------------
One thing I have certainly found with this project is the huge amount of detail changes involved in the progression of type 7C's and type 9C's over the course of the war. Each build will involve a miriad of engineering changes that I will need to monitor and list to make sure that I can get the sub to be as accurate as possible.
To help me achieve this I have turned to a number of aftermarket updates that are now available, which were not available 10 years ago when I built the 'Last Patrol' 7C/41 diorama. Companies such as CMK, RC Subs, Special Hobby and Shapeways 3D printing, plus the fact that Revell now have released 5 1/72 kits, enabled me to produce all the variations I want.
Revell kits - #05166, #05015,#05163, #05114, #05133. Special Navy kits #72001,#72002, #72006, RC Subs type 21.
Bring on the detail ......................