Yes I remember those, they had a subframe for the axles and landing gear, most box vans were like that as I remember, the Gray and Adams fridges with the little step in the sides were the same, a proper PITA to fit side boxes or spare wheel carriers to.
I know what you mean about weak floors too, we had some hanging garment step frames that got used on general groupage, they were no problem until you went to Italy, where a trailer is only loaded when they can’t fit anything else inside it.
Because of that the firm I pull for (and many others) get shot of them after 10yrs, as a lot of customers won’t load a trailer older than that. Even with new trailers you have to be careful if loading heavy stuff, I once loaded 21ton of nickel pellets on 7plts, three right over the pin and four over the trailer bogie, loaded straight down the middle and they would have kinked the trailer.
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