Beautiful rare Derogy lens

Recently i bought a very early beautiful Derogy petzval lens for my small collection.
Every time i say to myself, i have to stop collecting stuff, but this one i couldn't resist......

The lens is dated between 1850 - 1860 so more than 150 years old.
A beautiful example of perfect handcraft.

The bayonet system makes this a rapidly convertible portrait/landscape lens.
The lens has a focal length of about 8" and it's speed is about f 3.8
unfortunately it has no flange, so if somebody could help me finding one i would be more than grateful !
Thread diameter is 88,6 mm.

I made you some pictures to show how the ingenious lens works.

 Standard portrait situation

fast opening with bajonet

 It has a double lens cap which can be taken apart.
One for the portrait lens and a smaller one for the land scape lens

Here you can see the aparture rings which were used in very early lenses

Mounted as a landscape lens including the smaller lens cap mounted at the front