I've read the post, read all the comments - only have a little to add.
First, here is 'stall' and there is Stall and 'it depends'. For the purpose of developing an operations handbook, flight tests will focus on three conditions - Gear Down/ Flaps down, Gear Down/Flaps up and level fight 'clean'. There were no flight tests for non-asymmetric flight conditions which is a whole 'nuther ballgame in theoretical study.
Hard to do analytically because 'real' analysis requires very sophisticated tools to model abrupt surface changes (like landing gear wells, gaps, protuberances, etc) to point to flow properties and discontinuities (like separation) - all required to model real aircraft instead of wind tunnel models.
So, for estimates of CL vs alpha, the wing section properties for 2-D Lift to drag shape (optimal) is the start. Next calculate 3-D effect of Aspect Ratio to degrade the CL vs alpha and L to D from Optimal - with stall characteristics and shape after CLmax. Next further degrade Lift to Drag as function of wing plan Geometry. The eliptical gives lowest Induced Drag, then look at Tip to root chord ratios for further calculated increases to Induced drag - with 1:1 being least effective in mitigating Induced Drag from optimal based on planform and MAC.
Either look up your airfoil for Section properties and wind tunnel 2-D (infinite wing span) data - take your wing to the WT and develop your own. If proprietary, like NAA/NACA 45-100 there are complex math solutions to 2-D section properties.
You are are getting closer to the expected clean wing aero properties - but nowhere close to Performance studies as the System Lift and Drag properties (wing/body) are not yet fully determined. You need both and recall that CL and CD in performance calcs are Normalized on Wing Area but, for example, are calculated for the entire airframe weight and in inclusive (but not stated) of all lift and drag contributions of the fuselage and empennage.
Not to mention Exhaust Thrust, Carb pressure drag, Cooling Drag and Vortex contributions to Profile drag to all the other Parasite/Profile Drag delta's to add to Induced Drag contribution (high in proportion at low speed). Prop and Prop Thrust is carefully scrutinized for the low speed conditions.
Then later, take to full scale wind tunnel and see how you performed your preliminary analysis.
The above is particularly important for a Mustang -
This preparation and assembly of data/estimates in the preliminary design stage shapes a lot of discussion regarding washout considerations (another increment to parasite drag), aileron area, flap type and size, landing gear location (in/out of vortex from prop), etc. Much of the same data is also required to estimate take off roll and landing roll runout.
All interesting, but - a pilot wants to know what to expect from his airplane at low speed, dirty and all the above discussion is mostly noise. Personally I was also interested in the characteristics of breaking to final approach in a banking turn.