I used to get through quite a lot when I was still in business although,
as they contained solvents, they were all plastic lined. From
experience, you will probably find a few dumped around the back of units
on local industrial estates, depending how long it is since the
Environment Agency had been around to nag about not leaving them there.
As you don't need it in pristine condition, you might find an industrial
chemical supplier has one or two that are past being reused.
Colin Bignell