Purchased from The Imperial Shave. They make and sell various types. They are very nice and as a single unit piece they are easy to use, but as I just mentioned above, I feel they are a little larger than the genuine item found on W&B and many other vintage razors. I'll have to search out that thread you mention, as I would prefer to use triple stack washers.
Yes, the washers are nice and look great IMO, I have several done like that with brass washers, from traditional 2-pin to custom 3-pin, black and blond horn.