This is an interesting approach, but I would like to offer the observation that this sort of funnel-shaped washer might not always be a good choice. This is for two reasons.

First of all, the cut-away illustrations you have included show a fairly generous hole in which the pivot pin seems to have an excessively small diameter. A properly-sized pivot pin should 'just' fit the hole in the razor tang. Of course, if it actually does fit correctly, then there will be no additional room for that funnel-shaped washer to sink down into.

Second point. On many razors the hole in the tang is not perfectly round. In fact it will be seen that many an older razor has a pivot hole that is elongated or deformed to a greater or lesser degree. If a funnel-shaped washer is used in this circumstance, then the 'funnel' of the washer will necessarily be forced down into whatever space it can fill (assuming again that the pivot pin is too small and does not fit correctly) and may very well become 'keyed' to the elongated hole so that instead of serving as a friction reducer between tang and scale the funneled washer will instead be forced to rotate with the opening and closing of the razor. The end result of that might be rubbing and wear between the outside of the funneled washer and the inside of the scale.