Greetings, a few answers...perhaps.
Regarding the modulus of the coupon. It depends on the stacking sequence of the laminate. If this was a tensile only coupon, with all 0 degree tape plies, using "standard" intermediate modulus graphite, then the stiffness will be around 16-18 Msi. If it is plain weave cloth, then the stiffness will be 8-9 Msi. Now, when you test an actual laminate say [45/0]2s, of cloth, the axial modulus of the laminate will be much lower, in the 6-8 Msi range. Again, it really depends on the material and stacking sequence.
You can find a lot of public information on different graphite material at the following sites. Note that this is from an FAA database which is used in some aircraft certification programs. Your results may differ slightly depending on how the coupons were processed.http://www.niar.twsu.edu/agate/Documents/default.htmhttp://www.niar.twsu.edu/agate/Documents/default.htm
You can also find lamina data from the manufacturer (Toray/Hexcel/Cytect/etc)
One other thing to remember is that matrix (resin) dominated properties will be much more sensitive to the test environment. The temperature and humidity must be controlled in order to get meaningful results. This is less of an issue with the testing you are doing, but once you start testing for strength, the difference can be large ~30% for OHC (open hole compression strength)
Hope this helps.