Euan, nobody can, because it's not in cultivation.
I guess there will be some specimens left of it at old Arboretums but not among us members of this forum...

Well its in cultivation as i have two very small plants
here.Sure there are many old culivars that are lost but
may turn up again.

I would like to see a picture of your small specimens, Euan.
Does it have a fasciated growing habit?

-Sam

Sam

Will post a photo the plants dont have a fasciated
habit however this form does have slightly twisted
branches.

If it's only showing some twisted branches then it isn't worth the cultivar name 'Cristata'.
It should bin named 'Contorta' or 'Torulosa'...

Here is my rooted cutting Edwin do you have
one in your arboretum can you post a photo?

Euan, no, I don't have it any longer, lost it last winter together with the 'Pendula'...

That's pretty cool.

Dax

Nice! Certainly looks worthy of returning to culture - at least at a young age.