What tubular track turnouts/switches can accommodate Marx locomotives with fat wheels?

[The Railroading Phoenix]

Hello, I recently acquired a prewar Marx 597 Commodore Vanderbilt, and it has a single-reduction "fat-wheeled" motor, and rather than replace the original motor unit with a later double-reduction unit that doesn't have fat wheels like I originally planned on doing, I've changed my mind, and decided that I'd rather keep the original motor unit and instead modify my layout to accommodate it, at least on the main oval. However, my layout uses a mixture of O and O27 tubular track, including switches. The problem, then, is that while I know that all Marx and apparently Lionel 1121 turnouts can accommodate fat-wheeled engines, those are all for O27 track, and in order for my Commodore and any more fat-wheeled engines I may get in the future to fully traverse my layout's main oval, I would also need to get an O-gauge switch with an O-31 radius on the diverging leg that can handle fat-wheeled engines, and I don't know of any such turnouts. Do they even exist as ready-to-run items, or am I gonna have to get creative and either modify an existing switch or custom build something that'll most likely be incredibly janky?

 

[Dub]

I am not that familiar with the problem. Marx switches will work and if you are not happy with any postwar switches, how about looking at prewar switches? I have one or two I can test out with the fat driver.

 

[The Railroading Phoenix]

For context, my layout is an oval with some sidings, and it uses O27 tracks and switches for straight bits of the oval, but O gauge track for the curves at each end, and built into one of said curves, there's a switch that leads to a spur. The thing is, Marx switches won't fit in said curves due to the Marx turnouts being O27, which has a 27-inch diameter curve on the diverging leg, while I'd need a switch with a 31-inch diameter curve on the diverging leg to replace the current Lionel one. I've been pointed towards prewar American Flyer O gauge switches, but there's very little documentation online as to which ones are O gauge, and would therefore work, and which are O27, and would not

 

[Dub]

Prewar AF switches are easy to find. Just look for any three rail AF switches. 027 is a Lionel thing and not made by AF. The switches look like Marx. Made in 1938.
You can fit in a 027 Marx switch. Add curves to make a 90 degree section and cut straight track to fit. Same for the 031 side.
Fat drivers have the best chance of moving through an o22 switch if the fat tire is on the center side. If it approaches the left turn if the wide tire is on the right it will make it. If the tire rides the outer rail it will jump. With a dremel you could widen the outer grooves.

 

[The Railroading Phoenix]

O27 was created by Ives, which was jointly purchased by Lionel and American Flyer, who both produced it before AF sold their shares to Lionel

Technically speaking, yes. However, I want to keep the O gauge curves because there are locomotives that can't handle O27 curves, and as long as I keep the O gauge curves as they are, I can at least run them on my layout's main oval, but if I swap in some O27 curves, I won't be able to run them at all

 

[Dub]

What I did was throw up an elevated loop. Run anything up there unimpeded.

If you visit Myflyertrains.net check out page 35 of the 1938 catalog. It states O gage and has dimensions.
Ebay has some inexpensive manual switches. Hope this helps.