i just obtained several series VI filters for my crown. the step-up adapters that came with the filters don't fit the lens that i have so i need to get the correct size. i understand there are two types of adapters...
ones that slip on the lens & screw-in thread types. the lens is a 135mm f/4.7 wollensak raptar in a wollensak rapax fully-synchronized m-x-f shutter.
the person i got the filter set from said that the adapters fit on an optar lens he had but they won't fit mine so there must be a slight difference.
what can anyone recommended for this type of lens & are they still available new from any manufacturer? or is eBay my best bet to get what i need?
thanks.

Accurately measure the outside diameter of the lens bezel (this should be smooth) I'll bet it takes a 1 1/4" slip on.