Here's my Hulkbuster MOC, wanted to make it as accurate as possible while keeping the scale. Yes you can fit an Iron Man Minifigure inside very easily : r/lego
Infinity War Hulkbuster Mark 2 MOC (more photos in the comments) : r/lego
Iron Man Building Blocks Hulkbuster | Building Bricks Sets | Iron Man Block Sets | Toys - Blocks - Aliexpress
LEGO Hulkbuster MOC by moxi (front) | Lego iron man, Hulkbuster, Lego super heroes