Conrad invariably pronounced my name with the extra consonants and an umlaut.
"A Fool and His Money"
George Barr McCutcheon
A number of words were printed both with and without umlaut.
"Facts About Champagne and Other Sparkling Wines"
Henry Vizetelly
Also, special German characters like U with an umlaut, and French characters like a's and e's with various markings above them were ignored, replaced with their closet single-letter equivalents.
"Correspondence of Wagner and Liszt, Volume 1"
Francis Hueffer (translator)