I had a very similar problem in Vancouver Canada.On the bright side - I remembered in time to ask for metal toe taps for the last order.
On the less than bright side, for my previous pairs, - the cobbler I spoke to in Boston so far has told me he does not use metal, as people "have complained in the past", but rather plastic.
I evidently don't want plastic toe taps. The search will continue...
Most of the cobblers looked at me funny when I told them what I was after. Some of the suggestions I received were quite ridiculous.
I was actually only able to find one place that does Toe Taps correctly, and this is in what is supposed to be a world class city.
I get the feeling that the high end shoe market is quite tiny outside of NewYork, Toronto, and London.