Piper Cub J3 and L4 construction numbers

[De rode ridder]

When I look at the different L4 serial numbers, there is an airframe construction number that goes with it. Some times they follow each other by 1 digit, sometimes they don't. The USAAF s/n for eg. Jumps by 1 digit and the c/n by 12. Those gaps were J3's???? Can I conclude that all construction numbers of wartime piper cubs are chronological? And when they are not going together with a Military serial number, they are J3's?

Thank you.

 

[longwinglover]

 

[De rode ridder]

 

[De rode ridder]

 

[longwinglover]

 

[Jorgen]

 

[FreddyK]

 

[Renkou1]

 

[De rode ridder]

 

[FreddyK]