The chief station master said " I have never had even one seller tell me if a whistle or horn works, so I guess they never "go over" those .".
He must have missed most of my Ebay locomotive/tender listings. If it's a Lionel tender, I almost always say the whistle work - few that I haven't been able to do that.
Horns are another story. Here's what I say in a current Ebay listing.
I cleaned and adjusted the horn relay and it is now working properly. The horn has good sound. Anyone familiar with Lionel diesel horns knows they are problematic. I don't know if it will work after shipment, so all that I can assure the buyer is that this horn was working well just before I packed the unit for shipping.