Looks great! I'm in the beginning phase of building my own Mark V armor. As you noted, the original Legacy maquette (and lifesized statue) that was made is vastly different from what appears on screen. The Hot Toys Bust and figure are pretty accurate to what you see on screen, while the lifesize statue is of the original concept only. There are a whole lot of differences (like the cuts on the helmet, the silver chest pieces, and even the abs).
Your build is quite an inspiration!