Ed, you really need to change that filter! I could be wrong, but on your car the driveshaft may have to come down to get to it. On the 500/Freestyle it's pretty accessible.
Here's the filter cap on my original filter @ 90K:
And here's the new filter:
Nitehawk, the filter part number is Volvo PN# 30787687. That includes a new top cap, o-ring, spring and bolts. I don't know if there's a Ford equivalent-bdcardinal will know. The filter from Volvo is $20.00 or so online. It's easy to remove; 2 4mm allen bolts hold the filter cap in place. Remove those and pop out the filter. Installation is the opposite of removal... The filter location is in the upper left in this photo. The bottom part sticking out is the Haldex pump. Above that, recessed to the upper left is the cover for the Haldex filter. The new cap is a bit different than the old cap (rusty car not mine!):
For the Haldex fluid, there's no substitute, either Volvo's Haldex fluid or Motorcraft XL-13. You'll need at least 300ml on-hand.
For the front PTU and rear differential, you just need a GL-5 rated fluid. The PTU has an additional "low foaming" spec, BOT-1 or something. I've been using M1 synthetic 75W90 front and rear for the last 60K miles and all's well. As mentioned, there are only fill plugs so you need to pull it out with a vacuum pump. The Haldex and rear diff bolts are right next to each other, Haldex towards the front of the car, rear diff towards the back. Here's a bad picture where I'm pointing to the bolts:
http://i56.tinypic.com/2cpt3rm.jpg
The front PTU/bevel gear is best accessed from the front. Here's the bolt (picture taken from behind the unit):
http://img695.imageshack.us/img695/9185/ptufrontsidedrain.jpg
One note: draining the Haldex and rear diff fluid require a bit of patience, but you can extract most of the fluid pretty easily. The front PTU is more difficult and requires a lot of playing around w/the tube. Use vinyl, not rubber, so you don't cut it on a gear and get it stuck in there. I did 3 drain/fills getting out 8-12 oz each time. Total capacity is roughly 30oz.