Nikor Part

I took delivery today of a Nikor tank with six reels, a lifting rod and one extra part. All of the parts appear to be new old stock. Each reel is inside a plastic bag inside its box and with instructions. The extra part is an aluminum band which fits inside the tank between the topmost reel and the cap. I think it is supposed to keep that top reel from bumping up against the bottom of the top. When I first saw the band I thought it might be part of the condenser assembly of an Omega B22 enlarger. Has anyone else seen one of these bands for a Nikor tank?

I got my tank and reels new in 1974 and have the manual. No mention of the band or picture of it. Maybe you can find a manual for the larger tanks if it is used there.