Although I have been exploring the Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+) for over two decades, it is not the only unorthodox opening that I have researched.
There are, of course, the twin lines 1.e4 e6 2.d4 d5 3.Nc3 c5 / 1.e4 c5 2.Nf3 e6 3.d4 d5, which Riley Sheffield and I covered in our book The Marshall Gambit in the French and Sicilian Defenses in 1988.
I also examined 1.e4 e6 2.d4 d5 3.Nc3/Nd2 dxe4 4.Nxe4 Qd5 in a trio of articles in the "Unorthodox Openings Newsletter" (#4, #5, and #12) in 2001 and 2005. It is fun to be able to quote from "Recent Play in the Frere Variation of the French (Part 1)"
The variation 1.e4 e6 2.d4 d5 3.Nd2/c3 de 4.Nxe4 Qd5 has been given several names. It has been referred to as the Becker Variation, although nobody I’ve contacted, including Eric Schiller, has been able to explain why. I have called it the Frere Variation, after the American Walter Frere, who analyzed, played, and referred to it as his in the 1920s. Certainly a case can be made for calling it the Katalymov Variation, after Boris Katalymov, who played the defense against Keres in Moscow in 1965 – perhaps the best-known example of the line – and against Shinkevich in 2001and Filchenkov in 2002. Andy Soltis, in his Grandmaster Secrets: Openings refers to the line more neutrally as the “Neo-Rubinstein,” acknowledging that the first three moves of the opening are often attributed to Akiba Rubinstein.
I have since seen the opening referred to as the Maric Variation, in light of Yugoslavia's Honorary Grandmaster Rudolf Maric's games (I have found 4 of them).
It is pleasant to see Brazil's FIDE Master Justo Reinaldo Chemin playing the defense - as recently as 3 games this year.
By the way, all 39 issues of the "Unorthodox Openings Newsletter" are available from Editor-in-Chief Lev Zilbermintz at the UON website. They make for fascinating reading.
Oh, and of course the UON also includes articles that I wrote on the Jerome Gambit, which replaced my interest in the Neo-Rubinstein variation.