Here are a few:
Dear Sir or Madam
your XYZ organization
from 1977 through 2007

the rest sounds OK.

Thanks a lot, Helmi!

Dear sir or madam

I found your address in a magazine and would like to learn more about your organization “XYZ”. (Entweder den Namen ODER 'your organisation' – mit 's' für GB bitte!).

Let me first introduce myself: (lasst das "to you" weg)

I am a retired 55-year-old flight attendant from Austria. After my training in hotel management I worked with the Dutch airline KLM BETWEEN 1977 AND 2007.
I would describe myself as a loyal, honest, reliable and flexible person.

Since I am interested in spending one to three months in England – preferably in Cornwall or Devon – and working for your organiSation, I would like to ask whether there is a chance for me to get a job ON this project. (You work on a project not in it).

I am looking very much forward to hearing from you.

Best regards (OK, better when you know the name of the addressee)

(or Yours faithfully when you use Dear Sir)

Thank you, Hotmetal!

It's a pleasure Dan, and ich drücke Dir die Daumen.

Hotmeal,

'Yours faithfully' is VERY old-fashioned. It's not wrong, and when writing to an 'important' person it may be the safest thing to do; but it really is borderline. Hardly anyone these days would think twice about 'Yours sincerely'.

'Organization' is not wrong in BE. I say this as someone who ALWAYS uses 's' in such words, but it's still not erroneous to use 'z'.