Tried downloading your pics and marking them up but for some reason nothing would recognize the file and allow me to edit it.....so....

I would do the parts I mentioned earlier "
1) 1 the plate on the underside cushion lever bridge (87s),
2) 2 the left side swing arms bolt cover plates (both sides, in & out) and weld up that gap on the bottom cover where it meets the lower frame rail.
3) 4 top plate of the seat latch cross member and flat gusset it to the frame rails front & back
4) 2 the front of the front down tubes where it's a 90
5) 2 the front of the upper frame tube where it ties in to the front of the shock towers
6) 4 Horizontal (flat) gusset the shock tower bridge to the frame rails front & back (BE CAREFUL NOT to fill up the clearance to get the radiator in & out) use your radiator to test fit these gussets before welding them in
7) 4 Horizontal (flat) gusset the lower frame cross tube (in front of the steering stem bushing)
2 horizontal gussets in back of the front motor lower cross member


May be a bit of overkill but if I had PC'd my frame 60% of it would have been ground off for repairs.  I only paint my frame as each season I seem to have cracks that need repair, Duplicolor Old Ford Blue at O'rileys.