
to the CCF, Tom1212
I honestly don't see the counterstamped half bringing any premium from a collector of this branch of exonumia. IMHO, counterstamp aside, its value largely rests in it being a better grade type coin that's suffered
PMD.
This likely one-of-a-kind counterstamp was created with the application of individual letter punches. These tend to be less desirable/valuable that those made with a single, prepared punch.
What really adds desirability and value to a piece is when a counterstamp can be definitely attributed to a specific issuer and meaningful history can be attached. Here's a pair of counterstamped
Seated half dollars that illustrate what I'm saying ...


Not only were these two coins produced by the same dies, there's enough info to identify the issuer. Add to that the history, the subject matter, and you have a winner.
Parisian Varieties was a "girlie show" and forerunner of what we now know as the Rockettes - a chorus line of leggy gals. It was quite a controversial show during the Victorian era, 1875-76. Much has been written about it in early newspapers and through present times. The counterstamped coins then circulated and generated word-of-mouth advertising. Today, these pieces tend to sell for $200 or more, depending on the host coin and interest of the bidders.
If I google, "May 20, 1877" and "truth" (use quotation marks as it discriminates and limits returns), I still get a large number of returns. The info is all too general, too broad to pin any significance to the counterstamp. Also, counterstamps that simply illustrate initials are virtually impossible to attribute; this, discounting silversmith hallmarks and similar craftsmen logos.
Summarily, I can only venture a guess that the subject piece's counterstamps MAY have had some religious meaning to the maker (C.F) and receiver (F.N). The word "TRUTH" leads me to that assumption. In essence, I view this counterstamp as more of a love token, expressing personal sentiment. This use stands in stark contrast to the "Parisian Varieties" advertising pieces.