In my experience, the Lledo ones look roughly 1/50 scale, while the Matchbox ones are more around 1/60.
These are the Lledo ones (don't have pics of the matchbox ones, but I got those to go with a true 25mm ~1/60 scale project):
And the plastic figures that come with some of them might give an indication of scale too:
Also, as a general rule, vans and small trucks will always be smaller than cars within the same brand due to the fit-in-the-box scale, so Lledo vans will likely be closer to 1/55-1/60. Demonstrated here (back row):