I have seals but no way to ACCURATELY measure them, other than a ruler. Webhead should be able to hook you up with new seals and gaskets.
You shouldn't need a puller to remove the clutch. Should be a bolt or screw which holds the center clutch part to the shaft. Some shafts are D shaped, some are tapered shaft. You'll need to look down inside the center, under the clutch springs. Think the blowers used the bolt with a 5/16 head. I can open one up and get pics if needed. The clutch pictured from the winch is an old style cork lined clutch, I believe yours should be steel with 2 flat springs spanning the center hole. Pretty sure this is a drawing of your gearbox.