This guy sells reproductions of plans for Sterling Mambo series in various sizes $10-15. The original plans did not have patterns for formers so you have to "extrapolate".
http://members.tripod.com/~TomDixon/plans4.htm
The 48" w/s version was my first successful R/C model in the 60's.
I may cobble up a stick and tissue 36" electric version with undercambered wing and lifting stab for slow indoor an calm morning flying similar to my Dare Marionette. Would use my Faigo 12mm IPS motor in a GWS DXA motor and small 2S lipo or tiny 6-cell NiMh pack, GWS RP4 rcvr and one Hitec HS-55 servo for slooow rudder only flying.