Moby
GOLD Star
A couple of years back I rebuilt my stock from seats in my FJ-62. I used Specter's replacement bottom seat foam and marine grade vinyl upholstry and added seat heaters. This was a substantial improvement over the previous state of the seats. More importantly my wife loved it 
The only remaining problem was the lumbar support or lack thereof. A couple of months ago Car Craft did a short series on rebuilding stock seats. I decided to give a couple of their suggestions a try.
I added a layer of 1/4" closed cell foam to the entire seat with extra in a couple of really broken down places. Easy to cut with shop scissors. Used spray foam glue from Home Depot to stick it to the stock foam. I also tied the springs together with coat hanger wire.
I haven't really tested it out yet but so far there is a noticeable difference. The upholstry fits much tighter and there is much less sag when sitting in the seats. My wife says that she noticed the improvement immediately.
Probably $40 total for one seat, with the foam being the bulk of the cost. Took me about 4 hours to do one seat (however it went faster this time since I had already done the upholstry once and knew how it comes off and goes on).

The only remaining problem was the lumbar support or lack thereof. A couple of months ago Car Craft did a short series on rebuilding stock seats. I decided to give a couple of their suggestions a try.
I added a layer of 1/4" closed cell foam to the entire seat with extra in a couple of really broken down places. Easy to cut with shop scissors. Used spray foam glue from Home Depot to stick it to the stock foam. I also tied the springs together with coat hanger wire.
I haven't really tested it out yet but so far there is a noticeable difference. The upholstry fits much tighter and there is much less sag when sitting in the seats. My wife says that she noticed the improvement immediately.
Probably $40 total for one seat, with the foam being the bulk of the cost. Took me about 4 hours to do one seat (however it went faster this time since I had already done the upholstry once and knew how it comes off and goes on).