I use Andy's method!
I have a jewellers punch set: a sold steel block with a slot cut in the middle and a series of holes of different diameters drilled through it. It has a set of flat topped punches that just fit in the holes. It is intended to produce circular plates of various diameters to use in enamelling (which I did in my foundation year of college - many (gulp!) years ago!), but if you get thin enough shim stock and pre-drill centre holes it makes good friction washers. You can also vary the thickness of the washers by using different shim stock, to even-up a blade by using different thickness friction washers on each side of it. Expensive (and I have just tried googling it to see where one can be had but all I keep coming up with are dapping sets - not suitable) and low-tech and with my present amount of experience only 3 out of 5 (on a good day!) are properly centred. It is a bit of a chore to use so I wouldn't consider being a supplier.
I have pretty much given up the use of the Dovo washers - just too thick and as Andy points out the centre hole is a tad too wide.
A better success rate could be had by someone with a mini metal lathe, I would think - just drill the centres, over-size punch the washers, put them on a spindle that tightens (like the mini nuts and bolts from micro-fasteners) and sand then to an even diameter while spinning. I have done this with an over-sized wood lathe so I know it would work, but the wood lathe is a bit of a cumbersome beast to use. The last time I turned out a batch that had to be precise I pressed the drill-press into use - much more convenient.
If you can't get one of those die kits, even a paper punch will knock out passable disks out of thin shim brass, and a wad punch set would get you different diameters.
Regards,
Neil