There seem to be at least 5 sites according to RCAHMS. Maarten van Hoek reported that the one shown in the Beckensall drawing (Bal craig 1?) is now completely covered over, he says the same of another panel which I think is Balcraig 2.
But RCAHMS lists Balcraig 3 at NX 3759 4429 and Balcraig 4 at NX 3754 4440 as still being uncovered. Another unnumbered is listed as simply Balcraig, at NX 3774 4440.