Measure the endplay before you take it all apart, that will tell you if you need any different selective washers. A washer kit is available with all the thrust washers and a couple of common selectives. Get a book and read through it before you start, it might save you some time headaches. Overall it's pretty easy to freshen one up. Don't stress, just get into it.
If filter is clean I'll reuse it. My beater truck has 194K mi and AFAIK the filter is original. I know nether one of the Grand Marquis have seen a filter replacement.
Maybe I'll try and get a nice fancy filter.... $200 rebuild -> $400 filter Just kidding (but I'm sure they prob exist)