Towing weight distribution display

[Toolmaker51]

Besides kind of a high profile, Unistrut is satisfactory anchoring material. Initially that was what I'd planned to use also. Bolted down [open side up] 12" to 18" apart, with large diameter washers or strip stock averts bowing or tearing floor. That figured into a trick for strap hooks. I'd keep a bag of Grade 5 carriage bolts [one wrench] and lock nuts handy, placing to accommodate payload through side holes, fit strap hooks through the slot and over the bolt. I suspect a good measure stronger then engaging anchors to the slot alone, and hooks stay in place before tensioning.
Then a good deal for unused surplus E-Track appeared...

So, before this 'deployment' in California, I'd built a pair of E-track for my 5 x 10 tilt bed. It's single axle, wood floor for 3500 pounds. Original anchors are just 4 wimpy 1/4" wire loops; OK for ATV or a ride-on mower, household goods and such. Always had to hook into openings of angle iron that form side walls too.
Had very little confidence when it comes to what I've hauled, machinery; tall, heavy, small foot print, often narrow as well. Such things never have built in attachment points, you have to wrap dunnage over sharp edges, bind a strap and cinch up while maintaining desired tending angle. A 36" 3 wheel bandsaw wasn't bad, compared to an earlier 36" 2 wheeler almost 9' high, the press brake of a couple years back, a turret mill, 48" shear, various grinders...
All by myself, Egyptian rolling them on peeler cores, pulled by a high-low geared boat trailer winch. Tilt beds tell you when any load centers over axle, but the axles aren't centered to length of bed, you MUST pull further to raise tongue weight. My method uses estimated weight, and distance from front edge of load over axle to position when trailer tilts up indicating some state of balance. All those tools had huge differences of weight, profile and CG. Can't say a particular tongue weight is the goal, just the higher percentage of weight is forward axle centerline, guesstimating that winds up 60% - 70%. Only the two wheeled saw needed repositioning, wandering as much as the toy in the video clip, right at 60 mph.

PS. Thought I'd google an image of that 3 sided strut material; it IS NOT Unistrut, slotted but without any holes on the sides. The solution mentioned with 3/8-16 tab and screw eye is better there.