The problem with donating items such as these to any museum is that they never see the light of day afterwards unless a very serious researcher knows of it and uses it accordainly.
If I was in a position too I would have the log book professionly copied including the front and rear covers looking like the original, just like the After the battle team did with Guy Gibsons log book and then sell copies to the public which after normal costs paid out the profit would go to relavent charities.
This way not just the infomation would be shared out worldwide but also charities would also benifet.
Just an idea.

Regards

Jay