Old Toy Train Collecting:
      https://www.trains.com/ctt/how-to/expert-tips/knowing-what-to-collect-when-collecting-toy-trains-and-electric-trains/

Guide to model train collecting:
---- https://www.americasantiquemall.com/post/all-aboard-our-guide-to-collecting-model-trains

  

FACTS:   

Louis Marx and Company made classic O and O-27 gauge toy trains from 1934 to 1975. They cost less than Lionel or American Flyer. They used stamped tinplate metal and simple motors. Many collectors still buy and run them today. 
=====    Most of what I have are windups from the the 1940s;    see http://www.whatoofind.com

* American Flyer was a popular 20th-century toy train brand best known for pioneering realistic S gauge model railroading under the A.C. Gilbert Company.
Origins and Early Years
Founded in 1907: William Hafner and William Coleman started the American Flyer Manufacturing Company in Chicago, Illinois.
Early products: They first made wind-up (clockwork) and electric toy trains, competing directly with Lionel.
Name change: The company officially changed its name to American Flyer in 1910 as trains became their main product. [1]

The A.C. Gilbert Era
Bought in 1938: Alfred Carleton Gilbert, creator of the famous Erector Set, bought the American Flyer brand.
Post-War S Gauge (1946): After World War II, Gilbert introduced 1:64 scale "S gauge" trains.
Two-Rail Track: Unlike rival Lionel trains that used a third middle rail for power, American Flyer used a more realistic two-rail track system.
End of an era: The A.C. Gilbert Company produced these trains until 1966, when production stopped. 

===== Most of what I have is pre-war and then into the 1940s.    see http://www.whatoofind.com

CLUBS  

SD MODEL RR ASSOCIATION:     https://sdmrra.com/  (SD)
LA MESA RR CLUB     https://tehachapipass.club/  (SD)
SD 3 RAILERS:  https://www.sd3r.org/     (SD)
SD S-GAUGERS:   https://sites.google.com/site/sdsgaugers/    (El Cajon  Parkway Plaza)
AGGTA (all gauge toy train association  ) :    http://www.agtta.com   (SD)
  (Tucson, AZ)
  (Tucson, AZ)