Quick, probably dumb questions from a transmission novice

Thanks again to everyone for the helpful info. Even though I probably could have removed and replaced the seals from above, I decided to go ahead and drop the valve body. Seemed to be the better way to do it.

One last stupid question...there is a metal flange surrounding the mating surfaces of the valve body and accumulator piston that continues with a "dogleg" along the front of the housing. It looks like there would be further disassembly required to replace the flange and I'm not sure I've even found the correct replacement part yet. Does it need to be replaced or will it seal again if I reuse it? It seems to be less of a traditional gasket and possibly something that can be reused, but I don't want to put it all back together and have issues because I didn't replace it. Thanks!