They should be able to use footage from the Avengers or even deleted footage of the Helicarrier. Also, if it is rendered in any way like the ships in Star Trek, that shouldn't be too much of a problem showing it again in the series.
And I'm sure they can use the interior set.
Also, it's easy to just film additional footage during CA:TWS which would be part of that movie's budget. That's the good thing about being linked to the movies.
What are the chances that we will see the big sky ship in this series?? Also, dod you think they will break out the flying cars?
I'm really curious about this. Many of us assume they have their own base of operations. But in the trailer we clearly see Coulson "parked" his car in a flying hangar of some kind. I don't think SHIELD has two flying bases.
I'm kind of liking the Cargo plane, but I doubt it's the base