Interesting, Andy! Here in South Africa, Eitel is occasionally used as a given name and pronounced A-tel (the A being the vowel in hay or MAbel).
Quite a few German names are used here - we had some German immigrants in the mid-19th century during a period of unemployment back home, and they left placenames like Hamburg and Berlin, and some given names as well. And then there were also some Lutheran missionaries ... but which of them would have used Eitel, I do not know, and until our records get computerised I won't find out!
I've only seen it used here by Afrikaans speakers, hence the unGerman pronunciation.