Thanks to 5991erd and Brax's recommendations, I thought I had found a quality cobbler in B. Nelson. But, before sending my shoes in, I thought I'd check with them if they perform the type of work I am looking for. So, I sent them a couple of emails with a few pictures to illustrate my words, and, since I was not getting any answer, i thought I'd send them a message through their website.
They did answer this time, but, their answer was quite unexpected and left me befuddled.
Below is the message i forwarded them:
"Dear All at B. Nelson,
I am a serious shoe amateur and I am desperately looking for a quality cobbler in the U.S. that could install some thin protective rubber soles (e.g. Topy Elysee or Topy Top Gum - or any other brand - 1 mm or a little more but less 2 mm thick) and some toe taps on some of my leather soles shoes (Rather expensive and precious Goodyear welted shoes such as Edward Green shoes, for example).
You have been referred to me on a shoe forum as the one cobbler in the U.S. that could do the kind of work I am looking for. So, I thought I'd give you a more precise idea of what I'd like to be done:
The added rubber sole should not just be glued right on top of the shoes leather soles. Rather, the top layer of the leather soles should be skimmed off (the same thickness as that the rubber soles but without completely cutting through the stitches) so that, once added, the rubber soles lay flat on the leather soles as if they were part of the leather soles themselves.
The toe taps rather than just be hammered on top of the shoes soles should be flush with the shoes soles and screwed on (some little pieces of wood are inserted in the soles to receive the screws and brass screws are preferably used to avoid rusting after wearing the shoes on rainy days).
I forwarded you 2 emails at firstname.lastname@example.org to which I attached some pictures to illustrate exactly what I mean but I have not received any answer from you.
Could you, please, let me know if you would do this kind of work, and, if yes, for how much?"
And, here is the message I received back from B. Nelson:
"Sorry but I prefer to stay away from this order.
No answers to my questions, and, no explanation for turning me down??... I find this weird...
Would you mind sharing your experiences with B. Nelson? Do you see anything wrong with the message I forwarded them?... I am all perplexed by their answer!