Choo-Choo Johnny - As PaperTRW stated, the NYC matching PB unit for this set had full RailSounds and, since I have the matching Santa Fe PA/PB equivalent of this set, believe me when I say the PB’s full sounds (including additional horn sounds) are terrific, especially when combined with the PA’s horn - thus producing a multi-chime effect that’s one of my favourites. So my advice to you would be to keep your eyes out for the PB unit (6-18966). Trust me - you won’t be disappointed!
As to whether Lionel ever released a matching PA Dummy - I agree with PaperTRW that they never did.