Hi Diego! I hope this helps:
A fixer is a contractor who 'fixes' or books people for recordings or concerts. American production jargon for a re-recording of a poor performance.
www.sudeepaudio.com/glossary_details.php
A shilling was a coin used in the United Kingdom, worth one twentieth of a pound, 5 new pence, or 12 old pence prior to 1971.
http://www.answers.com/topic/shilling?cat=biz-fin
With regards to the word "above", it refers to the year mentioned above, that is, 1941.
Keep in touch! Regards
