KPNuts,
I believe that you are doing a great job in straightening out that warp.
Concerning the differences between the Airfix and the Revell kits of the Wasa, I have both on my shelf and can offer the following points.
1. Both hulls are cleanly molded with precisely the same lack of molded-on wood grain on the planks.
2. The gunports are quite different, although the dummy ports on the Airfix kit are deeply recessed. The gunports on the Revell kit are open, and the kit provides full-length cannon barrels, but the gun carriages on the Revell kit are molded onto strips of plastic that run the full length of the gun decks. There is a solid wall immediately inboard of the carriages that would leave no room for any gun crew to exercise the guns. This, to me, is a big distraction that must go away when I build this kit.
3. The Revell kit has a single-piece that contains the main deck, half deck and poop deck where all of the topside decks snap into place, while the Airfix kit has all decks as separated, individual pieces. The Revell kit reminds me of the old Pyro kits with this feature, although it is a little more cleanly and finely molded than the Aifix kit. Plank details are well molded on both.
4. The topside railings a very different on both kits, Airfix having a more ornate arrangement while the Revell kit railings are plain.
5. The wales are separated more widely on the Revell kit. Both kits show a total of eight wales.
6. The Revell kit has more detailed and finely shaped gun barrels.
7. The Revell kit has solid plastic shrouds and ratlines, while the Airfix kit contains the Heller-style shroud and ratline loom on which to make your own.
8. The chains on the Revell kit are really nice, while those on the Airfix kit are rather plain.
9. Boat detail on the Revell kit is better, being very crisp, excellent planking, benches,oars, and internal detail.
10. Both kits have what appears to be equal hull lines and dimensions. Both are excellent kits.
I hope that this helps!
Bill Morrison