Thank you, that is a very kind thought and part of me wants to accept if only to for the experience. Electricity-free fettling has a definite appeal.
Realistically, however, I do not drill many holes larger than about 12mm and I am probably too lazy/inept to keep the bits properly sharpened. So I will pass on your offer. I was thinking more of donating the bits to someone who would use and appreciate them, ideally someone to whom they would make a difference.
Phill