The interest is that many of us have feet which aren't catered for by standard sizes in commercially produced shoes. There are two answers to that: hand-made shoes (frightfuly expensive) or make them yourself. Spouse has made all mine and many of his own (including all our Roman, Dark Age and Mediaeval ones) for years but now he's being asked to cater for others.
I thought someone here might know more than we do. It seems that they don't, which is fair enough.
There's a huge amount of untapped knowledge on d-i-y skills in this ng, any question is worth asking.