Go with what Brett said.
However, I've also had good results with the old Top-Flite 9-6 wood props.
I have a few of the .201s and there is virtually no difference between it and the Fox .19.
Having run quite a few of these from the 50s, like the .19, .201, .25, .29 and .35, I caution the use of mufflers.
I have tried a number of different mufflers and most if not all have caused overheating.
I have hundreds of flights on the above mentioned sizes and I've used only Brodak 10/23, 50-50 oil and all the engines run perfectly.
The engines were acquired both new and used.
Bill Mohrbacher (SP?) told me that the reason for the .201 was to be able to use the same plane in two different classes - A, up to .200 and B, .201 to .30.
Bob Z