The Graupner Cirrus was the plane to beat in the early '70s. It and the Cumulus epitomized the "fast and heavy" end of the design spectrum (very European even then), as opposed to the "floater" types like the Oly 99.
The Cumulus did have a plastic fuse, but it was one piece, whereas the Cirrus was 3 piece.
For more info and some photos of both kits, see:
http://www.skybench.com/nostalgia/sc...crapindex.html
RCM had an article (June n'75) on how to make a "Super Cirrrus" which involved adding polyhedral, and a larger rudder and stab. Basically making it into an Aqula
My advice: don't. Build it stock and warp back to 1972.
Cheers,
Dave