The Spitfire Mk IX ? What Merlin engine variant? 61 or 66 or 70???? Octane fuel ? 100 is only a 16 pounds boost engine or is it the better performing 25 pound boost using the 150 octane fuel. Clip wings are great but I would much rather have the 25 pound boost engine in my Spitfire with regular wings. So which one are we going to get?