guide recommendation for a Florence study tour for a history buff

You might check Rockyruggiero.com . He is based in the US but goes back and forth to Florence frequently and does private tours. He is an art historian.

Here's Rocky on youtube: https://www.youtube.com/results?search_query=rocky+ruggiero

Also on youtube, recordings of the British Institute in Florence's Wednesday lectures: https://www.youtube.com/@TheBiflorence

The art history classes at the British Institute are great and include walking tours --- you can take just one class on a subject that interests you. It also offers this tour in June: "In June, we also are running 360⁰ FLORENCE which acquaints participants with the history of Florence through a series of historical walks and museum visits. The perfect introductory programme for new residents, students, or anyone who'd like to know the city inside out, and discover its many wonders." When I took a month of their art history classes in person and then lots of others on zoom, I found that they were about half and half art and history, which I liked. You can visit their library, too.

Check out Elaine Ruffolo's Sunday lectures on zoom (free but a donation is nice) and she also has some on youtube: https://www.youtube.com/results?search_query=elaine+ruffolo

I believe that Elaine, like Rocky, does guided tours in Florence.

We've only gone on one Tours By Locals tour but it was very good and tailored to our interests --- they are well worth looking into: https://www.toursbylocals.com/Florence-Tour-Guides?utm_source=google&utm_medium=cpc&device=c&network=g&matchtype=p&campaignid=19476347909&devicemodel=&adgroupid=140136046770&utm_term=tours%20by%20locals%20florence&gclid=CjwKCAjw4ZWkBhA4EiwAVJXwqSne0YPfWKwh7exG0lCxIpeIeNvsSZweWAWqqUHdpqx8RETorNc3ixoCJSgQAvD_BwE