Best 1930-1940's era scale 40' flatcars currently available?

Well, depends on what you mean by “currently available “.  AHM and Pola made a pretty decent 40’ flat in the late seventies, but it was designed for 2 rail.  You need to add your own trucks/couplers and most likely repaint and decal into your preferred road.

Here’s one of my for sale cars up close with a Sherman loaded; my own wooden deck to cover the plastic deck of the model:

Here’s an overall pic of one of my for sale shelves with a AHM 40’ center front

These cars are pretty commonly available, and I would never pay more than $20 apiece for them.  I usually try to buy in bulk and get them down to between $10-$12 apiece, seeing as they need new trucks, paint and decals before they’re anywhere near ready for revenue service.

Hope this helps.  Any questions feel free to ask.

Cheers,

Price

While Lionel's PS-4 Pullman Standard flatcar is a postwar design, it is probably the nicest mass-produced flatcar in O scale.  Alternatively, the Menards 50' flatcars are surprisingly nice for the price.  I have several that I have plans to repaint for correct paint schemes. 

I agree with Johnathan on the Lionel’s as far as out of the box. I model a road with not much offered in 3RS. I look for Weaver’s with minimal lettering. I remove 2 unseen ribs on the chassis which allows you to really lower the car. Rough up the deck and paint it a wood color. Shave off some molded details. Add scale size stirrups, grab irons at the car ends and a new brake wheel with a more scale size shaft. Then re letter.

Addendum:

I would be remiss in not mentioning that Lionel acquired the molds for the AHM/Pola 40’ car and produced them as their Std O flatcar in the early 80s.  Lionel then kept using them (with some truck modifications) up to recently.  The most prominent examples I can cite are the Lionel Route 66 flats with ceramic (?) cars, and the “Peace Automobile Sales” flats with VW Beetles and flowers painted on the decks.  The bonus for buying the Lionel editions of these cars is they usually come with die cast trucks.

Cheers,

Price

@Dave_C posted:

I agree with Johnathan on the Lionel’s as far as out of the box. I model a road with not much offered in 3RS. I look for Weaver’s with minimal lettering. I remove 2 unseen ribs on the chassis which allows you to really lower the car. Rough up the deck and paint it a wood color. Shave off some molded details. Add scale size stirrups, grab irons at the car ends and a new brake wheel with a more scale size shaft. Then re letter.

I would love to see which ribs you are talking about and how you lower the car.

In order to lower the car you have to commit to Kadee’s. Leaving the claw coupler off lowers the car a bit. The trucks are now mounted to the chassis like the 2 rail version. The larger 3 rail flanges will rub on the 2 inboard ribs of the chassis. . I just trim them off as they aren’t noticeable or really necessary. If needed I can shoot you a pic..

Good Evening Everyone,

As Jonathan posted above,  the Lionel PS-4 flatcars are very nice scale cars but note they are 50' flatcars,  not 40' flatcars.   Lionel also makes very nice diecast,  scale 40' flatcars with a wood deck.   Both the 50 and 40 footers ride nice and low on their trucks.   I own numerous of both and are great for custom loads.   I usually scribe the planking lines deeper into the wood then rough up the surface a bit before staining the wood with various Minwax stain colors.   Used to be able to buy nos Lionel 40 footers for $25-$35 and the 50 footers for $35-$45 but those days are gone as prices have gone up considerably,  especially for the new product.   Here's a few photos of mine.