Thanks for all the responses guys!
The beep people in O scale are too small ( alot like the heads in the Dorfan cars), I have a few.
The JLM and LGB are a bit beyond my budget. ( I think it was MTH and Lionel that did a study in O scale that resulted in eleven figures per passenger car as an appropriate number to make a car " look" occupied. Should hold true for 418 series cars.)
I'm going to continue to search for COLOR silhouettes and maybe just populate the window frames not the seats. I dont think the O scale black silhouettes as used in the " Irvington/Madison " cars of Lionel or the Marx cars would be as eye catching as the color ones used by Williams.
Of course the William's ones would need to be photo enlarged to almost G scale dimensions.
Best Regards to you all. I' ll check back if I find a source and solution.
