Are there any good translations and guides of Fiore's 'Flower of Battle'? I'm not just looking for something that has a taste of Fiore's system, but a complete interpretation guide even if some of the interpretations are outdated. Something similar to Tobler's 'Secrets of German Medieval Swordsmanship'... At least of one of the sections if not the whole treatise.

Bob Charrette's book is a good start.
http://www.freelanceacademypress.com/armizare.aspx

Here is an old thread which might be useful:

https://myArmoury.com/talk/viewtopic.php?p=169881

A few years ago when I had time to regularly practise HEMA, our group started out working from Colin Richards's Fiore interpretation; he gave us a course in person, but more relevantly to this thread he also wrote a book on the wrestling and dagger section (which we used afterwards). The book was quite detailed and well illustrated with photos of the steps of each technique, and worked fairly well for us.

Guy Windsor's Swordsman's Companion was released for free a while ago since he thought it was becoming too obsolete to be worth updating (and he ended up writing an entirely new book instead). Dunno if it's still free on his shop.