Hi Ron,
I am not sure whether the unit markings match the front plate. If I am correct AR27 RBA18 is stamped into the neck guard, which would correspond to artillery regiment 27 and reserve bekleidungs ambt of the 18th armee korps. Those two marks are consistent with each other. However, AR27 was a hessian regiment and, which does, therefore, not match the Prussian front plate. But perhaps I am wrong here and I agree the blurry pics don't provide much confidence.
Best regards,
Edwin