Dash binnacle brass fixing, S3

After turning the Landy on its side I've lost one of the binnacle fixings (i'd replaced the the set screws with a stainless one 1/4unf x 1/2 long) but I've also lost the brass thing that sits in the back part of the dash binnacle. Is it called a ferrule?? From memory its about 1/2 long and has a knurled outer edge. Any idea where I can get one or what size I'd need to replace it?
FFG

Is it a nutsert.
https://www.ebay.co.uk/itm/100pcs-C...47675.m570.l1313.TR8.TRC2.A0.H0.Xnutsert.TRS0

Thanks, never heard of one!!! Take it that its 1/4 UNF thread? Any LR suppliers have them? Anyone have a part number (is it 79240)?