Woodhead shocks (Blue) value

[75 911s]

I have two decent rear shocks that came off my 1975 911s

I think it was originally equipped with them as I see some midyears came with them.

I've read Woodhead is a British company that was under contract from Boge to do these.

They apparently came on a lot of 912e cars.

Are they worth anything? Thanks in advance. Also if anyone has Bruce Anderson's book - there is a section that talks about this shock. A pic of that page or just quoting the text would be awesome.