1908 Autocar truck engine, where to sell Options

[stumpjumper]

I have a older coffee buddy who has a 1908 autocar truck engine he wants me to find a buyer for it.It's a 2 cylinder, horizontally apposed.air cooled.He's had it about 40 years.He used to take it to some engine shows and run it in the back of his truck.It was rebuilt when he was showing it.We tried to start it the other day.It did start but ran on 1 cylinder.Other coil is not sparking.Anyway I'm looking for a good spot to list this thing or find someone who could use it.
He used to live in burbank and said he showed it to Jay about 20 years ago, but Jay was looking for a water cooled one at the time.He was told it was worth $2500 back then, but says he will take that for it now.