Model 68|Winchester .22 Rim Fire|Forum|Winchester Collector

My father gave me a Model 68 bolt action rifle when I was a kid.  He acquired the rifle himself as a kid during the second WW.  When he purchased it, it was fitted with a Lyman peep sight mounted over the bolt.  The peep sight was long gone by the time I received the rifle and I was wondering if anyone knows what model Lyman it might have been and can they still be found.