Matt, can you do me a favour and count the reflections in your lens? If it has 6 elements in two groups, similar to a Dagor, each cell should have two strong and two weak reflections. If it has an 8-element construction, like the one shown in the first attachment, I believe that it will have two strong and three weak reflections.

Both figures taken from David 1911, Photographisches Praktikum. Lehrbuch der Photographie.

Cheers

Claes