Your right, jayz. ~175g does sound more reasonable. *rueful expression*
Nic, I built a FB DLG two days ago, and I got it fairly light. The main problem I keep on running into is the foam getting soft on me. The wing tends to deteriorate within 70~80 launches. I can get a good 100ft of altitude, but even with the elevator at zero and no real vertical G-force (only horizontal G's) the wing will fold eventually. The only way I can see to get a FB DLG strong enough is to get 1mm by 5mm by 1000mm spring-steel flat stock, and glue it in the wing like you do with your nnMig-3, and your other speed planes.
This would not be the lightest way to do it I will grant you, but the alternative is a good CF/fiberglass job (which would cost more then I would like--or anyone else for that matter).
Oh, almost forgot: Another way of doing it is to use a 750mm x 5mm x 1mm piece of CF from HK in the wing. I have not tried that, but it would be much more effective (and ligheter) then the small hacksaw blade I have in my wing.