His handwriting is actually all over the place - which suggests he doesn't use it much. But it's certainly intriguing. Is there a graphologist out there in SBO?
I am not a graphologist but I do have a book about it called Handwriting Fundamentals written by Paula Sassi and Eldene Whiting.
"by all over the place", if you are referring to how he combines both printing and cursive script, according to the book, this combination indicates ingenuity and good problem solving abilities. It may also suggest as you say that he does not write very often. But, while the book also mentions that, it says it's because penmanship is a "practiced art". When we fall out of practice, people tend to get lazy with it, especially when we feel pressured or hurried. People who use this combination on a regular basis, are often very balanced and are constructive and practical thinkers who relate to both tangible and the non material aspects of life very well. But also, when written slowly, it indicates someone who is very conscious of revealing their emotions, it indicates a need for privacy.
I love this stuff and I think it's all very close to the mark!
P.S. The shipping from the UK is almost $50 USD which is currently higher than the bid for the item! So, I am going to take a pass, but I am so tempted!