Pulled my 25 year old jacket out of the closet (Field & Stream label) and tried to get the dust off of it before taking it outside and using a can and a half of silicone/water-repellant on it to see if more life can still be squeezed out of it.
I'll let it dry outside until the sun goes down, then bring it inside the garage to finish drying, for 24 to 48 hours as the instructions on the can recommended.
I haven't worn it much at all over the last ten years, but my Pa might could use it when he's out and about. It's thin insualtion wise, so it doesn't help much below temps in the 40's unless you wear layers beneath. Lots of pockets though, and makes a good rain jacket, and I especially like the longer length on it.