Paramount serial number quest
 

I have a track bike with serial number; N610. I am having trouble dating it. I am thinking it to be mid sixties.
The fork looks original but it has oval blades with a drilled sloping crown. the crown matches the bottom bracket. Should it have rounds blades. the lugs are nervex but the bottom bracket does not seem to be stamped nervex.
Any help is appreciated.
thank you , J.

Pics?

Your Serial Number equates to November 1966, the 10th frme made that month. Pictures please.