Find a book on line, local hobby shop, or in the library............
Or just punch in the numbers of rolling stock and / or engines/locmotives in a search engine using goggle or any of the others and you will have some idea as to value. HOWEVER it may not be an accurate value as it is all relative...... depending on the condition of your set...............good luck in your search! SIDE COMMENT>>>>>>>>>>>sites such as this one "Choo Choo" OR "Train City" are just about the best you can find for information...........but most of us "old farts" don't get up real early and I don't check my messages every day so hang in there..........wait and read!
I can find no reference in my AF 0 gauge books to a locomotive numbered 4602. I do find, however, a locomotive/tender 4603.This locomotive/tender were made in 1938, the year AC Gilbert bought the American Flyer company. 4603 is AC Gilbert's number for what was originally 3181. Your engine/tender should have the remote reversing feature and since it was made/sold in 1938 the tender should have what collectors call the "curly Q coupler, or sometimes a sheet metal knuckle coupler.. Now, as for value, Greenberg's AF Prewar O Gauge (2nd edition - 1997) estimates a value of between $35 and $75; Doyle's Standard Catalog of AF (2007) places the value between 150 and 300; and Train City's price guide based on a sale in 1994 places the value at $155.
My guess, however, is that you have a train set. AC Gilbert's 1938 catalog says it's train set #2 featured at 4603 locomotive/tender with remote control reverse and "automatic couplers" (a k a curly Q, etc.), 3019 dump car with tilting side, 3015 box car with sliding doors, 3018 oil (tank) car extremely realistic (yeah, right!), 3017 caboose with lighted interior. The set came with a 40" circle of track. AC Gilbert says if you bought those separately it would cost you $11.90, but if you bought them as Set #2 they would be yours for $5.95. Oh yes, you'd need a transformer and the catalog recommends either a 50 or 75 watt transformer, which would cost an additional $2.50 or $3.75 respectively. According to Doyle the values of the cars may range from between $15 and &150! but generally in places such as www.trainmarket.com you'll see them valued closer to the bottom than the top of that range. Doyle is not always a reliable guide to pricing.
If this is what you have, you might consider trying to sell it as a set (especially if you have any of the original boxes). Doing that will move the price/value up. Good luck.
