Oh, I'm going to sound so evil here. All ideas above are great, but will require a great deal of time on your part to change, maybe majorly killing some great scenes?
It's your story and authors take creative license all the time. If you like it the way it is--keep. Then do a little thank you following with a disclaimer... "Our sincere thanks to so-and-so for his/her expert advice. S/he is not responsible for what we did to it." You can also put in a disclaimer explaining the reality of the character from the normal timeline if you like. I think... No living relatives can sue, right?
Ask the question, "What would Jim do?" LOL It is alternate history right?
I attended a small writer's group at a weeklong workshop with Michael A Stackpole. We spent, I swear, hours on one woman's story arguing that you CAN NOT make a curved, flaked bone knife. Get over it, fix it, or accept it and move on folks. Can you tell that true history buffs or extreme tech science guys are not going to read my stuff? I research like hell, change what other's find wrong that I can, but the story being told is what I have to use in the end if there is a conflict between those.
Best wishes. meg