i have a 85 720 4x4 that's been my daily commuter for the past 4yrs roughly 90 miles a day and like all of us i love these trucks, about four month ago my 720 blew a head gasket so i figured id go over the whole truck with a fine toothed comb and replace all the ( oh god how did i drive that long like that parts) that seem to always show up in groups so large you wander if your going senile for missing them all . now most i can fix but some i cant seem to find anything about or find parts for, which I'm hoping y'all can help me with.

The first would be the front cab mounts they've rusted completely through about a half inch all around the mounting bolt in the cab floor, not sure if i should just weld some sheet over the gap (i know it wont be structural) or do they sell floor pans for these trucks like the older Chevy's and Fords.
The other big one right now is the... not sure what its called i think its called a tension rod mount? or compression rod mount ( 8 to 10 inch long rod flat on one end two bolt holes other end goes through bushings that compress around it as you tighten it to the frame helps keep the lower arm stable, the outer washer rusted out and fell off some time ago and the frame mount is all wallered out so any suggestions on how to fix it would be appreciated ill try to get some pics tonight and post them, I'm still new to forums and posting on them. thanks for your time and help

Do a google search for the floor panels as it seems there are companies that sell them. In regards to the torsion rod mount you said the washer rusted out? Can you replace the washer and simply use a welder to add more material back to the wallered out hole?

I could add more material with a welder shouldn't be a problem i was just hoping for a better solution and as far as the washers are concerned i haven't been able to find any, same with floor pans plenty of pans for Chevy and fords but no Nissan's.