Hi Craig, i have been flying a 5 jet for the past two years with a mw54 mk1 12lbs thrust eng.
Just recently i have uprated it to a 14lbs, the performance is brilliant.
The 5 jet is very nice to fly but hard to slow down for landings not having any flaps fitted.
Models weight is 12.5 lbs dry, inc 4 oz of lead in the nose to ballance it.
I think you could save about 2 lbs with a mw44 and some carefull building.
It would be hard to save some weight on the wing withought it affecting the strength.

Rgds Martin.