The moon is cracking up! :0

Or the start of something more sinister like lens fungus. This is from my Nikon 35-70 f2.8D lens that has been with me for almost 20 years. It has spent some time in Central America, Europe, The Pacific Northwest and a vast amount of time in the Bering Sea. It now retires with me in Bonny old Scotland. If anyone out there knows of this issue and if it is worth repairing because the cost of replacing this with a newer version of this is about £1,300. At the moment it does not have any impact on the quality of the photos but I'm sure that in time it will.