I decoded it the same way, but there are trhree possibilities for this car:
Bonnevile hard top
Bonneville conv
Chieftain conv

How to prove that the car I have is true bonneville?

still no luck!!! they start from 1964 and 1967...

They provide only info starting from 1960

Hello! I bought 58 boneville conv at Mecum in August. The VIN reads P558H7777. The car has no cowl tag. Question - where can I get any info on the car to be sure that it is real convertible and not a conversion and is it possible to order anywhere the cowl tag info and reproduce it? Thank you for ...