No, you misunderstood. Very few U47/48 came with this transformer.
After Stephen Temmer, the Austrian impresario, started Gotham Audio with some of his friends, he convinced Neumann that he was the man to re-ignite sales momentum in the countries for which he negotiated exclusive representation: Canada and USA.
He immediately drove hard bargains with Neumann, and one of them was, that all mics delivered to his territory would need to be much lower in output, to better match the input sensitivity of antiquated stateside mixing consoles, hence, increase sales.
Initially, Neumann complied by simply switching its strappable outputs to 50 Ohms (-5dB to -6dB). But somehow, after a couple of years started to wind a special BV8 transformer exclusively for U.S. export: the BV8b. That shaved another 6dB off the output.
That damage was done very late in the life of the U47/48 (see my percentage estimates, how many mics were affected, in an earlier post of this thread.)
By that time, Capitol, etc. had probably already a full contingent of mics without the dreaded transformer, so chances are very slim that your favourite Sinatra records made between 1960, when the transformer first showed up, and 1962, when production of the U47/48 by and large ceased, would have used such mic (besides, by that time, Sinatra had switched to AKG's ELA M251 and various other mics).