INRD 9002 SD9043MAC ditchlights and what covers the hole

Model Railroader Prototype information for the modeler
1

I found some pictures of INRD 9002 and I have some questions:

What type of ditchlights should I buy?

What are the white covers below the walkway where the Kato put the model’s ditch lights?

2

Those are the covers for the MU cable receptacles.

3

Thank you, I suspected as much but wasn’t confident.