Mopac, perhaps this is before your Gilbert collecting days. The largest seller of Gilbert Flyer at the monthly DuPage train show was John Heck from suburban Milwaukee. The second largest was Bill Farner from St Louis. Bill made the trip to DuPage for 11 Sundays/year from around 1985 through at least 2009. I bought a few things from Bill. Back then there was a lot of Flyer around St Louis according to Bill. The S Fest was also held at least once in St Louis.