I saw a similar looking property near me having the paint removed only last week, I didn’t pay much attention to it but it looked like they were using a high powered pressure washer. Looked like it was doing a reasonable job but there were some bits of paint remaining
Instead of making the hexagons from 6 pieces make it from 1 length bent to shape, cut half way through where you want each bend then it should be fairly easy to bend accurately into shape. This will also leave a notch at each corner that you can use to rest the cross pieces in for welding.
I agree with Richiew mill scale is pretty rust resistant, try to keep it intact for as long as possible, my bench top is about 2 yrs old completely untreated and the only rust as a few spots where I have gone through the mill scale with a grinder.
I agree I’d love a pickup but I don’t want a 4x4 monster so I stick to a van .
In the distanced past I used a Peugeot 504 and a Subaru justy but there’s nothing available nowadays