The conversion from Corsair to SAAB is really quite a bit of fun! At times there are stumbling blocks that are put in my path but these have not been too bad. I get "modeler's block" sometimes and just have to spend time thinking through the engineering of the changes. The hardest part is making sure that the fuselage modifications could be constructed in such a way that the halves can remain split until final assembly.
Here's a couple more photos of the Corsair and B 17 fuselages joined.
SAAB B 17A In 1/48 Scale
SAAB B 17A In 1/48 Scale
This shows the first mock-up of the left stabilizer and elevator. Pretty straightforward in comparison to the vertical fin.
SAAB B 17A In 1/48 Scale