wrote:

Over the past few months I have been trying to buy a couple of
practical toolboxes for two or three different purposes.

About the best I've foudn for my uses are the Keter range. They have
many different types including a sort of stackable thing they call the
"MasterCart". The basic toolbox is pretty decent and it's strong enough
to use as a temporary support for cutting timber. The arrangement with
internal trays, dividers and external drawers seems to work well.

Find them can be PITA. B&Q used to do them but seem to have swapped to
own brand. Most of the ones I see now are sold on eBay. They are fairly
popular in the USA.