I’m trying to find out when this jacket was used and what is missing from the ribbon bar.

 

The name in the jacket is Strong.

 

Thank you in advance.

Here you go - https://www.29palms.marines.mil/Portals/56/Docs/Adjutant/Awards/USMC-Ribbon-Chart.pdf?ver=7gcnJp4uPcEZd8vmBihu8A%3D%3D

I’m not trying to ID the ribbons, I’m trying to figure out what’s missing from the 2 blank spaces on the bar.

 

Looks like a valor and campaign ribbon are missing.

 

The date of the jacket will help.

1986 looks too me

Could he have been in Desert Storm?

Well my guess is the AFEM is wrong and that it should be shifted right leaving a hole for the NDM. The top left ribbon could be any of these after the bronze star. That is my guess but certainly I would like to hear from any former marines.

My guess is it's missing a NAM or NAVCOM on the top row and the other two just slid down the bar.

 

Guessing it's a sea service deployment .missing on the bottom.

 

Good Conduct should also be after the two unit citations. 

The jacket is named.