An invariant regulator field method is applied to the construction of vector-current vertices in a dual resonance model. If it is not required that the regulators be fully conformally invariant, but only that they have the invariance required for duality, Gaussian factors can be eliminated consistently from both the elastic form factor and the deep-inelastic structure functions. This method introduces new ghost states which can be pushed to arbitrarily large mass by judicious choice of the regulator parameters. However, there are still ghosts at low levels from the basic dynamical oscillator field, as in the Veneziano model with intercept α(0)≠1. The structure function νW2 does not scale in the model. The physical interpretation of this result is discussed in detail.