You could set a global in the Machine table to the AttachmentID and make a relation from that global to that Attachment.
Then show the related container on the Machine layout, You could make that relation also related Machines::Attachment,
to be sure that the attachment does not pop up when you move to an other machine.
I have made a small sample to show the principle.
Hope that helps,
Ruben van den Boogaard
machines.fp7.zip 284.2 K
I understood your mail, I tried out your suggestion and validated what I had done against your example. Works great thank you, have to admit I don't know why I didn't think of that before as I have used that approach for other records just don't know why I could think of that sooner :-)