Another 8BA question

[flatford39]

Have what I believe to be a 49 Merc 8BA motor. It came without a transmission. I am putting it in my 31 Roadster. I am hooking it up to a 39 top loader and am using the cast iron truck bell housing. Will I need to reuse the piece in the attached pictures??? Doesn't look like I will need it. I am pretty sure it is a dust shield but I don't know what transmission it was used on. Merc o matic maybe?? If I do need to use it where would one get the gaskets??