Question for owners of flip top desk by Peter Løvig Nielsen  

Hi All, quick question for anyone with a flip top desk by Peter Løvig Nielsen for Løvig. Lucky me I just got one. Unfortunately the back leg strut is missing so I'm going to have to make up a new one. Can anyone pop up a picture of what the securing bolt head looks like as I can't find any photos close enough to get a best match.
I'm also guessing that it has an inset threaded sleeve in each end of the strut if anyone happens to know what style that was and how it was set it would be much appreciated.