I have an earlier version of this adapter from Century Tool. It has a thumb wheel needle valve that gives fairly precise control of the flame, but the earlier version is unregulated, and so requires periodic tweaking of the control to maintain a constant flame size. That's not as bad as it sounds, because most camp cooking is hands-on with frequent heat setting changes anyway, and one doesn't tend to leave pots on camp stoves to simmer for hours. The tube is steel and the orifice at the tip is yellow brass. There's an extension spring with a hook end that extends to grab the sheet metal of your Coleman stove to keep the adapter from falling out. (Original Coleman liquid fuel tanks hook into the front of the stove and so don't need such a spring.)
I've been using my adapter with a Coleman Model 424 2-Burner Dual Fuel(tm) Standard Compact Stove (Coleman fuel/white gas or unleaded auto gas) for about 10 years, effectively turning it into a Triple Fuel stove. The adapter accepts 1 lb disposable propane cylinders, or can be connected to a bulk propane cylinder by means of a hose, available here at Amazon.com and many camping/outdoor gear suppliers.
The only drawback I've found is that the adapter tends to sag and put pressure on the burner bowl. The hole in the front of the stove through which the gas generator tube from the liquid fuel tank passes is a vertical oval, a bit oversize, and allows the propane adapter a fair amount of angular play, more than it needs. When the stove is going full blast, the bowl gets red hot and softens, and the weight of the adapter tube plus disposable propane cylinder warps the bowl into a saddle shape. It doesn't harm the usability of the stove, but it looks a bit unsightly. I took the time today to remove the burner bowl, placed it on a fire brick and heated it to cherry-red with an acetylene torch equipped with a heating tip; I then pressed the bowl with a piece of heavy aluminum plate, returning it to near-factory condition. Afterward, I used a piece of 1/8 inch brazing rod (yellow brass) to fashion a clip that hangs on the front edge of the Coleman stove and supports the Century Tool propane adapter so that the tube doesn't touch the burner bowl. My clip design allows the stove grate to be lifted in the usual way for cleaning and stowage of the liquid fuel tank and various accessories. The clip now gets tossed into the stove along with the propane adapter and will go wherever the stove goes. Problem solved!