Very interesting thread, although I have difficulties to open the pictures... The company Petestein refers to, LSB, still exists. It stands for Leon Schuijt Bouwplaten, a publisher of paper models from Alkmaar, The Netherlands.
Bouwplaten literally means "building sheets" in Dutch, or in other words "paper models". I couldn't find the B727 model in the catalogue, but assume it still can be obtained.
www.leonschuyt.nl.
Good luck and take your time to complete your make-over.
Erik