Middle Wallop Engineering produced a scale combat model of this aircraft some years ago. I believe that the company is now defunct, but you might find a kit on Ebay. I have one of these kits, and might be able to dig it out of my storage room if you're interested.
Vanguard Vancouver sells a 75" slimer version: http://www.vanvan.us/wyvern.htm
Model Airplane News sells plans for a 36" wingspan version of this plane, with a documentation 3-view drawing, Plan # FSP0600A, June 2000.