Vigier Guitars

Hello! 
I just bought a new (to me) Excalibur Indus. It plays very well but I noticed that at least one of the string retainers was floating free without any retention.* The little hex screw will only go in so far, but not enough to capture the string. I examined the string retainer and it looks like something is blocking the central hole and hex screw. I'm assuming that since I do not see light through the center hole, that's a confirmation? I just ordered a replacement Flexretainer from the parts site (and realize now I should have ordered 2 sigh), but would greatly appreciate some advice/confirmation that this was the proper course of action otherwise I seem to have acquired a very expensive, yet very tiny paperweight.
Many thanks in advance,
Jeff
*I think the other one is doing the right thing as it doesn't move up and down with the string.

On the back of the head there is a housing that hold the flexretainer, there are two screws on the side. you must play with them to lock the flexretainer string.
Make sure the two screws are centered.(see on the right of the image)

We never made it with one screw.