It is very helpful when you are going uphill or just in some rocks and you stall the engine. Just put it low range and first gear and crank the starter without pressing on the clutch. The starter will turn the engine which will turn the wheels and slowly move you. The engine may fire up as...
There is a pad from toyota that fits on the hard top rain gutter to provide some protection.
63119-90030... it is $5
https://forum.ih8mud.com/threads/hood-bumper.1049832/
Think the only differences was between soft top and hard top versions but not positive. There should be a panel there.
https://forum.ih8mud.com/threads/north-carolina-door-headers-from.1364474/#post-15998578
When my master failed I would be stopped and gradually lose brake pressure and the truck would start moving unless I pressed harder.
Here is the FSM booster test...
I measured a new rear floor and mid bed panel (real steel) and they both were 40 7/8"
From this image it appears that the factory dimension is 1015mm which is more like 40" but as you found they are typically closer to 41".
Definitely welded by PO. All components of the frame are rivited togther from factory with the exception of a couple brackets in the front frame horns AFAIK