Wow, that bass was born a day after me. For some reason that strikes me as cool!
The 5 does not designate the 5th June. It's model 5 (Precision) and the neck was finished in June '64.
I was born in 1961 and so I was looking for a '61 but this '64 came along and well it was perfect. So I grabbed it.
Davo : )