Salesman/reps like Geoff Lindsay also seem to be a good place to find the odd large amount too.
And then there's the instance of a member of a construction team that had light fingers when dismantling a closed casino and saved 3 plaques (one of which is unique) for the hobby.
There are probably many more instances of "large" amounts appearing but let's hope they don't come out in drips and drabs.
I plan to show the unique find along with another that is rare on another thread.