a) The 'Beautiful System' has not yet demised. It is still in force for UK aircraft due to a non-acceptance of the EU standard which asks for far less than we have.
b) Your company can (and should) still use the references to BCARs, CAA Specs, AAN, FAD's etc, on aircraft built or imported to that standard.
c) Even after the demise of the 'Beautiful System', your company can still keep these standards as part of the Company Quality System if it so wishes, and subject to CAA approval - which, in my opinion, they cannot refuse as it is to higher standards. However, this may become a tripping point in later years as newer engineers replace us old hands who liked the old system.
Hope this helps.
Rigga