I think you're right in that you took a watered down sample...10 lbs of DME would yield, as you said, 1.074.
You shouldn't have a problem, except maybe keeping the syphon going when you rack if the bag tries to get sucked in.
[/I] Up Next - Hobgoblin
After That - Czech Pilsner
Primary - Humboldt Hop Rod (4/24)
Primary - NOT Wheat AG SNCA (5/5)
Conditioning - SNCA Clone (3/3),