step up adapters for Vintage 16mm Lens

[Manuel Virgilio]

Hello, I'm writing here to ask some information about 16mm vintage lenses.

I own two lenses:

- TAYLOR HOBSON 1" f1.9-22

- WOLLENSAK 17 mm f2.7-16

I'm want to use modern ND filters on them and I'm looking for some step-up ring adapter, but I don't know internal pitch and diameter of the actual filter thread (and where I could buy these adapters).

The 1 inch Taylor internal diameter is about 23mm and the 17mm wollensak internal diameter is about 19mm.

 

There is some way, with some kind of step up adapter or something else to use modern ND filter on these lenses ?

 

Thank you for your help.

Manuel