I've always wondered which locos these two Porter models were based on, but now that I'm adding sound one I want to know which whistle is most prototypical.
I've found a few on Youtube that look REALLY similar to Bachmann's On30 offernings, but their whistles all sound different.
In general, whistles were the choice of the buyer. In most cases with small locos like the Porter, they just ordered a "tweeter", a high single note sound, rather than a big chime whistle you would find on a big road loco.