We built ours out of 2x's that were not good enough for finishing lumber instead of cutting them up to throw into the furnace, we just used them for the tops, usually 2x6's or 2x8's, then screwed them to the cants we were also going to cut up to put in the owb, by using 2x's we don't need the strips below the cants, there's only top boards and the cants screwed together, mine are either 8 foot or 10 foot, with some hang over on each end of the pallet. That way all my pallets with lumber on them can fit through my planer shed door, think the door is 12 foot wide, so it takes some wiggling with the skid steer to get the longer stuff in pallet, lumber and all. Pretty simple and cheap, as they say make something useful out of nothing valuable, we must have made 40 by now this way, use the skid steer to move the loaded pallets around and stack lumber piles 14 feet tall to save space.
For lids on my lumber piles we stack outside, I just built some longer, maybe 12-14 footers and somewhat wider and screwed old barn tin to them, that way we just use the skid steer and once the lumber piles are all stacked up outside, we use the skid steer to set the lids on, and if needed, use a ratchet strap to secure the lid and keep it in place so the wind won't blow it off. All built out of stuff not good enough for anything else and the only out of pocket cost is the screws to screw them together.
If they get damaged, we just unscrew them, cut up the materials and into the owb they go and then use the screws to build another one, the materials are free as they come off the mill and the tin was salvaged off old buildings before we tore them down.