Okay, let's Old Skool this: Given the era you're working with you should be looking at a ratio of 12 pounds of weight per square foot of wing area, so, in this case about 420 sq. ft. of wing area (which gives a take-off speed around 62 m.p.h.). For the wingspan of 33' you want you would need a chord of nearly 13' - a very high drag / poor performance proposition. You should consider a 60' wingspan and a 7' chord (or, if you need a shorter wingspan, a biplane layout something like a Felixstow.) I would suggest the RAF 34 airfoil (or the RAF 15 if you want something undercambered.) You're probably looking at a cruise speed of around 100 m.p.h., so your flying time is going to be 45 hours. With your specified fuel load you will need to achieve a consumption rate of no more than 10 g.p.h. - again, you need an efficient wing to achieve this. For this era, you're looking at designing around 13 lbs. per horsepower - 385 h.p. in this case. I don't know if the Ferrari engine is going to be usable - has any Ferrari engine ever run flat-out for 45 hours? Finally, I think you should reconsider an S.39 type design. The roomy enclosed cabin is a necessity for a flight of this length in Arctic conditions. Besides, your cat could move freely on it's way to the litter box.