Hello mr. Fred
Thank you for sharing all this info
I'm especially interested in tire size, everybody putting low profile tires on 13" and that's not it. I know about middlebartongarage.com and Campagnola replicas.
Your project is by far the most detailed and accurate, you are building THE replica, most of other are wannabe replicas, just look-a-like (talking about OT Berlinas).
I was planing to build Mostra, but that project is now "off the table", waiting better days.
All best to you and to your OT 1600 Berlina project!
Regards,
marconi