Hi Andrea,
Just to say I ordered two black chrome MPs from Richard Caplan in London about two years ago — a very reputable firm that sadly has now closed down but I think more for health and pandemic reasons than anything else. Richard warned me that it would take a while and in the end the best part of a year passed but I was happy to wait. The cameras are great and for various reasons I then ordered a chrome one as well and had a while to wait for that as well. Why I am saying all this is simply to show it seems normal with this model.
Another long serving member of staff there, Emil, did tell me in passing when I asked about any reliability problems with MPs that they had not come across many; however if anything he felt that if anything this had been slightly more prevalent with custom orders ie. a la carte. (You mentioned you would be making an a la carte choice, if I understood you aright.)
I am very happy with the MPs as with other Leicas such as M4-P, M6 TTL and M7. The most finely engineered of all in my experience though are the earliest models such as the M3. So make sure you never try one; it might spoil you!
Good luck and let us know how things go.