Hello andrearossoni, I see this is your first post. Since you are seeking information regarding a Hostetler design I would recommend you post inquiries in the Scratch Builder forum: Scratch Building, Aircraft Design, 3D/CAD - RCU Forums (rcuniverse.com) or possibly the kit building forum: Kit Building - RCU Forums (rcuniverse.com)

You would get more responses in those above two places than here in Full-Scale Aircraft (not model size).