Horseman Rotary (Type3) / Leaf Aptus / Adapter

[PhotographCH]

Good Morning

I have a Sinar 4x5" with a Horseman Rotary Back that work very well with RollFilmback's.

Now I like to connect my Leaf Aptus 17, with Mamiya 645 mount, to this Rotary Back.

The Rotary Back has a Mamiya RB67 Mount Style.

Do anyone know, where I can get a adapter plate to connect the Aptus 17 with the Horseman Back.

Thanks