sounds like a late 59 to 61

mid 57 - start round small round glasstaillights with chrome rings.   center
brake light discontinued.  reflectors (n am market) also discontinued.  bezel
style plastic lens 'bubble' taillights/ bezel style flat glass taillights
discontinued

59  - first year of bumpers with overriders

late 59 (post mid May ch#469 329 or so)  discontinued 36HP motor + crank hole
apron

62 - now has plastic oval taillights and fried egg front turn signals - front
turn signals formerly cone shaped (n am)

in 66 the engine lid came equiped with a latch that has a push button.
 previously a square  nosed key, or church key was inserted into the hole in
the engine lid, and turned clockwise to open the engine compartment.  the
hole came with a chrome ring and cover that pushes to one side, but this is
usually missing.   some times a t handle is attached.

what mph does the speedo go up to?

does the back part of the front seat have a bump in it between where the
driver and passengers would sit?

is there  a gas guage?

is the shift rod short and straight and located close to the seat, or does it
 angle back towards the seat  and is located more towards the front?