Calumet Compendium shade

I've just acquired a Calumet model LS100 compendium lens shade (fits my 8x10 C-1). It's in good condition except for the arm that attaches it to the front standard. I'm puzzled about how it's meant to attach. I have one small screw dead center in the top edge of the front standard. I think there's supposed to be some kind of adjustable double arm secured to the shade, but I can't figure it out. Also, I know it takes 5x5 filters in the front, but what kind does it take in the back? Thanks for any help!

On top of the front standard, there should be a thumbscrew and clamping block, a nd also another on top of the shade. A chrome U-shaped metal thing slides though both of them.

I'll bet Calumet has the parts you need; ask for Jose in the parts dept.