It is true that Tzvi usually goes with Hirsch and for some reason Naftali goes with Hertz, but there are always exceptions. There was a Rabbi Shmuel Tzvi Hertz Luknietzky, and there are definitely other instances.
I also didn't mean to exclude the possibility that a father and son could be Hertz (or even Hirsch) and Tzvi.

Binyamin Kerman
Baltimore MD

you are partially right
Hersh is a translation of Tzvi, mostly people who are called hersh, the real name is Tzvi, and only called hersh, i know a few that are called Tzvi hersh both at a time but also rare, but very rarely (or if at all) will someone be called hersh alone,

Hertz ( even if the origin might come from hersh, which i dont know) i have never heard any one be called Tzvi Hertz, we hear alot Naftula hertz.
Zev and wolf, yes wolf is a translation of zev, we see some called zev wolf, rarely wolf as self

Tzvi and Hertz are not the same name, it only sounds similar to Hersh, but it is not the same and it is possible for a father and son to have tzvi and Hertz at the same time

If you have other gravestones, may I suggest that you post them on the ViewMate page.  It was created for that purpose, and is really the best way to get a gravestone translated.

Here is my reading:

==========================

At the top of the stone, inside the Star of David, a two-letter abbreviation meaning “Here lie”

========================== 

Right side:

Dear mother and beloved grandmother

LEAH BLOCK of the house of SELTZER [in other words, this was her maiden name]

Died on the 17^th of Kislev, 5730  [not 5760, as someone else read]

May her soul be bound up in the bond of life.

[This stone is a bit unusual, in that it does not include the Hebrew name of her father.  It does include her last name and her maiden name, which is also a bit unusual.  As to the date of death:  the 17^th of Kislev, 5730, began at sunset on November 26^th, 1969, and ended at sunset on the 27^th.  The stone gives the secular date as being the 26^th.  This means that she passed away between sunset and midnight on the 26^th].

==========================

Left side:

Reb TZVI, son of Reb Hertz

died the 9^th of Tamuz, 5723

May his soul be bound up in the bond of life.

[‘Reb’ is an honorific; it does not mean rabbi.  As to the date of death:  the 9^th of Tamuz, 5723, began at sunset on June 30^th, 1963, and ended at sunset on July 1^st.  The stone gives the secular date as being June 30^th.  Here, again, it makes it possible to narrow down the time of death to between sunset and midnight on the 30^th.]

--
Fredel Fruhman
Brooklyn, New York, USA

I would add that the abbreviation before Tzvi is for  Reb, a title more like mister than Rabbi. 
As an aside, the Yiddish names Hertz or Hirsch mean a deer, as does the Hebrew name Tzvi. Tzvi Hirsch or sometimes Tzvi Hertz are common combination names and someone known as  Hirsch or Hertz could actually have the Hebrew name Tzvi. In this case it is unlikely that Tzvi's father Hertz had the Hebrew name Tzvi since children aren't usually named after living parents in Ashkenazi custom. Another name combination is Naftali Hertz (the tribe of Naftali is symbolized by a deer in Jacobs blessing to his son), it is therefore possible that Tzvi's father Hertz had the Hebrew name Naftali or that he simply had only a Yiddish name.

Binyamin Kerman
Baltimore MD

Dear mother and beloved grandmother / Leah Block of the House of Zeltzer / Died 17 Kislev 5760.

Mr. Tzvi, son of Hertz / Died 9 Tammuz 5723.

+++

My comments:

1.  Gives Hebrew dates (remember that Hebrew day begins at sundown).
2.  Gives Leah's probable birth surname, and Harry's father's Hebrew/Yiddish given name (look for confirmatory info in other records)
3.  The English inscriptions indicate that they were survived by grandchildren and great-grandchildren (and for Leah, the Hebrew indicates grandchildren).   Such information can give clues to chase down as to descendants [Example:  Husband is listed as a grandfather, but wife, who died later, is listed as a grandmother and great-grandmother; indicative of a birth in the interim.]

Best of luck with your searches.

-- KHR
--
Ken Ryesky
Petach Tikva, ISRAEL
kenneth.ryesky@...

Belarus:  Gomel:  RAISKY, SHKOLNIK(OV), ARONOV, AEROV

Ukraine:  Yelizavetgrad:  Broad/Brodsky (also Odessa), Gertzig/Gertzog
Ukraine/Russia/Turkey:  Yevpatoriya:  Israelson, Arshenov

Rabbi Zvi Ben Herz
Jewish death date
תנצב"ה is a common inscription on tomb stones meaning may his soul be bound in the bond of life

dear mother and kind grandmother Lea Blak from Selzer family
Jewish death date
  as aboveתנצב"ה

(Here lies) Dear mother and gM Lea B:OCK nee ZEITSER passed away on 17 of Kislew( may her soul be bound up in the bond of everlasting life)
(HL )Mr Tsvi son of Mr Herts passed away on 9 of Tamuz (may his soul be bound up in the bond of everlasting life)

I'm no expert but I believe Harry is Tsvi, son of Hertz. 
Leah's stone says she is Leah, (I think it says her maiden name is "Zeltser"). 
Its unusual to show maiden names - usually fathers given name is used. Perhaps someone with better Hebrew can enlighten us?

Hoping someone can translate the Hebrew on this headstone. 

Thank you in advance.