Fake "RF" Overprints on Scott #C25 that I own.
Genuine RF over prints are very scarce with only about 200 known genuine examples and most are on covers bearing #C25 or stamped envelope entires with #UC3, #UC4 or #UC6. Shortly after WWII ended unused examples of “R F” overprinted stamps in singles, blocks and booklet panes appeared in advertisements and were offered by some stamp dealers. These were followed shortly by covers simulating some of the early examples, but uniform in stationary, dates and markings and missing some key characteristics of the genuine.
To be considered genuine all the literature I've read states that an “RF” overprinted cover must have the following characteristics:
Below are images of genuine RF overprints on covers with C25 or UC6 entires taken from the Spink Auction (starting with the last three listing on the page and continuing on for another page and ¾) website that show all of the characteristics listed above.
Another fine source of information about the RF overprints can be found in United States RF (Republique Francaise) Overprints On Air Mail Stamps and Stationary (1944 – 45) by Henry M. Goodkind, published by The Collectors Club of New York.
Most times on EBay there are a few listings of RF overprinted C25 in mint or used condition and on rare occasions a cover may be listed that does not show all of the characteristics that would make the cover genuine. What follows are a few examples of what I’ve bought on EBay.
This appears to be a plate block (no gum) of Scott #C25 with a Type f (CM6) “RF” overprint with a Poste Navale CDS dated May 3, 1944 in the selvage. First thing is the overprint is not a genuine Type f – the tail of the “R” is straight while on the genuine the tail of the “R” is curved. The “F” stands straight up and the top part of the “F” is almost as long as the middle part of the “F” while on the genuine the “F” leans to the right and the top part of the “F” is considerably longer than the middle line of the “F”. The images below are what a genuine should look like and a close up of the fake.
The next item is probably the most common of the fake overprints found on EBay.
This type of manuscript overprint is not known on any genuine cover and is not recognized as being a genuine type overprint.
The next two items are of the Type b (CM2/UCM2) overprint.
When compared to the known genuine Type b, CM2/UCM2 overprint seen below the two examples above are too neat in appearance.
I have is a cover that was bought on EBay. It has a C25 with what looks like a Type d, CM4 overprint tied to the cover with a Poste Navale CDC cancel dated Oct 11, 1944 along with a second strike of the same cancel just to the left of the tying cancel. It's in rough shape with bits missing at the top and the flap is separated from the cover.
Here is a close up of the RF overprint along with an image of the genuine overprint.
As can be seen the serf on the top bar of the “F” on the cover overprint has a curved inside while the genuine serf is diagonal on the inside. The cover overprint “F” does not have a period after it but the genuine overprint does have a period after the “F”. the overall appearance of the cover overprint is too neat when compared to the roughness of the genuine.
The back flap of the coner has a hand written note on the back that reads “Martha: Please don’t tear this envelope open. Save it for me”.
Here is one of two UC8 the provisional 6c on 2c air mail entires with the manuscript overprint that i picked up on eBay. In the United States RF Overprints on Air Mail Stamps and Stationary (1944-45), by Henry M. Goodkind, on page 46 – Fig 50 description reads “No verification can be found that anyone with the French Navy had the provisional 6c on 2c air mail envelope. Nor has any such postal stationary been seen used by the French Forces.” Goodkind also mentions in the next paragraph –“Fig 50 illustrates the only condition the writer has seen of such envelopes with Type ‘m’, Scott ‘e, all being uncancelled and unaddressed. One of the two entires had a small newspaper advertisment from around 1958 pasted on the back offering sets for sale. Unfortunately the company or person who put up the ad is not mentioned
In conclusion, all of the literature I’ve read states that any unused or used Scott #C25, #UC3, #UC4, #UC6 cut square cannot be considered genuine and are most likely a fakes or favor strikes made for sale to the stamp collecting world. Even if the overprint closely resembles or exactly matches known genuine overprints there is no positive way to verify that it came of a cover with all of the characteristics that make a genuine cover.
Here is a page that deals in Airmail counterfiets, fakes and forgeries with the first part specifically showcasing RF overprint fakes - http://jobi.bizhosting.com/AirmailCFF.htm
 United States RF (Republique Francaise) Overprints On Air Mail Stamps and Stationary (1944 – 45) by Henry M. Goodkind, published by The Collectors Club of New York, Page 60
 Opinions, Philatelic Expertizing – An Inside View, Page 110
 Opinions Philatelic Expertizing – An Inside View, Page 111
As always comments and suggestions are always welcome..