Hi Clint. the clear shot of 6666/18 is on p.11 of Ray's D.VII Datafile no.9.
There were 2 D.VIIs in Js12 with slightly different broom insignia and white nose areas different, but both probably Bessen's ?
The star D.VII in your photo seems to be in British hands but not the one Auer was shot down in, which had Js40 colours plus narrow tail stripes and was photographed with Soden who shot him down. At least that's how I see it; can't help with serials I'm afraid. I wonder if the one with a star on white band was Auer's ?
There are a couple more photos of it anyway ( don't help though!).
Nick
https://www.greatwarforum.org/topic/...-german-cross/