With gear and 4 appropriate size servos... I think 1 lb is workable for a .061 powered Aerobatic model. Not with a 600 mah battery in it... (cut that in half... save some weight, still have plenty of battery for the size model...)

20 years ago I had 2 channel model which was by no means light for its size come in at 1 lb even with the 600 mah pack and larger, heavier servos that what you could use today. And I had the hefty 7 channel Futaba RX in it... Work at saving weight using modern stuff... ( a Hitech 555 RX with the case removed and heat shrink tube... then foam wrap... save 1/2 or more of the weight of theat 7 CH Futaba RX with case still on it...) lighten the sheeted foam core wings (much heavier than they needed to be... sheeted with aircraft ply!) it would be easy to build the same basic 46 inch span design with the mods to make it 4 channel and add landing gear... and be very close, if not right on 1 lb.

Heck... the 2 1/2 lb is listed as MINIMUM weight for a .15 powered "SSC" (Slow Safe Combat? close... but not quite...) model made of COROPLAST! Some people are adding lead to those to meet the minimum weight!

Read up on 1/2 A R/C racers... they generally are 2 channel... but close to 1 lb, and have been for 15 years. New micro servos are amazingly light and powerful...
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Here http://www.hobby-lobby.com/threedee.htm

glow power convert that... bet you can come out under 20 oz... I can't find the ad for the electric Pattern plane they have been advertising to check its stats... The BATTERY in this thing is 6.9 oz of its 24 oz...