Rear axle check

Hey everyone, I was hoping to lean on the expertise of people who know more about this stuff than I do once again! So I pulled one of the rear axles to start the disk brake conversion and what I'm sure is a gasket came off with it. It looks pretty brittle and while I'm pretty sure it needs to be replaced I did want to check and get a second opinion. Additionally, this is everything besides the gasket that came out with the axle and I wanted to make sure that I'm not missing anything. Lastly I just wanted to ask if it looks like I need to replace the inner bearings and seals, and if there's anything I should do before putting the axle back in? All your help is greatly appreciated!

Old gasket off, New gasket on.

There is no inner bearings as far as the axle's go. Looks like you have the green ball bearing style axle bearings with the o-ring on the outer race.

Much appreciated. Those bearings are what I meant by inner bearings seeing as they go inside the axle housing.

I also wanted to ask if this is a gasket that needs to be replaced? I'm pretty sure the thicker part is metal but I'm not sure about the black part.

Also I wanted to make sure that I'm not missing any parts. When I googled gaskets for the rear axles I came across other parts like these and what to make sure I have everything so I can proceed with the disk brake conversion.

NOS Mopar Rear Axle Bearing Retainer 1965 Thru 1971 8 3/4 9 1/4 9 3/4 Dana Rear Ends - Hiltop Auto Parts

AXLE BEARING RETAINER PLATES - MOPAR 8-3/4 - Pair | NeratDemo.com

Last, I wanted to check and make sure this gasket set is what I need to replace the ones that are currently on the axle. If it's not, if anyone can recommend a gasket replacement kit it would be greatly appreciated.

P.S. I have a 67 charger with a 8 3/4 rear end if it matters.

Mopar Housing Gasket+Seal Kit for 8 3/4" (8.75) or Dana 60