Originally Posted by VictorM.
The outer, slip-on size is 27mm or A27. The inner, screw threaded size is 21.5mm. The original Kodak filters screw in to the inner threads, but are large enough to allow the hood to be slipped on.
Digging through my collection of series filter/adapters I found a 21.5mm series V screw-on adapter so I'm set when the camera arrives..