Hi all,
I have a mint Inon Straight Viewfinder from DiverVision for the Ikelite D810 Housing. It might fit other Ikelite Housings, but I think it'd have to be Nikon Pro Bodies. I'm using a 45 now.
It's a terrific viewfinder, I have a hard time imagining anyone not using a magnifying viewfinder on a housing to shoot with! It's as good as the Ikelite branded Magnifying viewfinder (not a surprise given that's an Inon finder).
Mint condition, no scratches etc.. Comes with spare O-Ring. You'll need an Ikelite Viewfinder tool to remove your previous VF.
$350 with free shipping, Priority Mail, US.