Handling quoted lists

[Urs Liska]

I'm feeling totally stupid, but after hours of nightly poking and
ly:message "debugging" around I'm at least at a point where I can ask
concrete questions instead of an MWE.

In 
https://github.com/openlilylib/oll-core/blob/master/internal/properties.scm#L566-L611
 (may not be the latest state!) I'm trying to create a macro and get
messed up with quoting etc.

In 
https://github.com/openlilylib/oll-core/blob/master/usage-examples/properties.ly#L10
 a symbol list demo.props is created and properly handled.

But in 
https://github.com/openlilylib/oll-core/blob/master/usage-examples/properties.ly#L50-L51
 a (quasi)quoted list isn't managed correctly. I would now use 
  '(demo props)
here to create a regular symbol list, but this ends up as
  (quote (demo props))
in the macro. When used later in
https://github.com/openlilylib/oll-core/blob/master/internal/properties.scm#L20
  (append '(_propsets) propset-path))
will result in
  (list (quote _propsets) (quote quote) (list (quote demo) (quote
props)))

Spo the question must be simple and me stupid, but how can I add the
symbol list as an argument in Scheme (in the macro invication) so the
last  call will result in a flat symbol list?

Thanks for any pointer, hint or solution!
Urs