That’s a genuine part of your bikes history. Was that the last time the bike was used?
A girl friend of mine had a very original 400/4, she had the F1 with the rear footpegs on the swinging arm. When we bought it, it still had the front number plate fitted on the front mudguard but it was a great bike and great fun to ride.
How’s life with the little one? She must be getting around on her own by now.