Answering question for Tolex - Marshall, Black Elephant, 52.5" Wide

Product:
Tolex - Marshall, Black Elephant, 52.5" Wide

Question:
I'm using this for a new back panel I'm making for my 1983 JCM800 4010 combo. Is this the correct tolex match? Also, I need 12 screws and the 'cupped' washers that match the originals. Do you also have those? Thanks, Steve