I guess Bulgaria because of the denomination in Leva.
Rolf Kirchberg (12 Sep 00)

Scott says the following after Greece #408: "Greek stamps with Italian overprints for the islands of Cerigo (Kithyra), Paxos [#243] and Lefkas (Santa Maura) are fraudulent."
Dave Lachance

This is one of those WWI era 2 heller charity stamps from Austria. As it says, it is to raise money for the troops serving in Bosnia.
Brian McGrath

This is a charity label from Sudetenland. (see: http://www.humboldt.edu/~rescuers/book/Chlup/chlupgif/czechmap2.html ) spende = donation (in German). The label probably dates between 1938-45, as Braunau was Hitler's birthplace.
Blair Stannard (13 Mar 2003)

This is a publicity / fund raising label issued by the Spanish Federation of Philatelic Societies. This was probably connected to a philatelic exhibition held at the time of the 5th International Fair of the Field, in 1962.
Blair Stannard (13 Mar 2003)

The stamp shown is a municipal revenue issued in 1925. You can find it in the J. Barefoot's catalogue Poland Revenues under Dubno (Powiat).
Sandro Tonini (31 Jul 03)

Cuba, Timbre Municipal. The set goes up to $10. The $5 and $10 seem to be very rare and they are not listed by Johnson/Rodriguez.
Rolf Kirchberg (12 Sep 00)

#249 - Mexican stamps of 1856 to 1883 are overprinted with district names, numbers and occasionally dates. This one (Scott #106) looks to be from Mazatlan.
Dave Lachance

Venezuela, Scott image type A16, #79, 87, or 91(unlikely). Used for revenue and internal postage. I would guess that the 'La Cubana' overprint (not in Scott) indicates revenue usage.
Terry J. Reedy

Turkey, newspaper tax stamp, 1st issue from 1875, 2 paras blue. See McDonald "Revenues of the Ottoman Empire", page 32, #1.
Rolf Kirchberg (12 Sep 00)

This is cut out from a Czech parcel receipt card. These cards incorporated a tax-this is a revenue stamp.It may also have been a notice card for a postal money order.
Brian McGrath

This is a charity stamp to benefit widows and children of postal workers. It is from Austria circa 1919 (date not accurate but close). The value of 50 Hellers was changed to 50 Krone because of inflation.
Brian McGrath

Some information about #254 but not an answer:
Betar is a Zionist (Jewish) movement. on the right upper corner it is the name Betar in Hebrew but not in the regular way that it should be written. I presume that it is some kind of donation stamp.
Rammy Molcho

This is a Yugoslavian federal revenue, circa 1920-1930.
Brian McGrath

I have got some more informations about stamp No 257. According to Jay L. Kaplove's catalogue of the Jewish National Fund, it was issued in 1918 on the death of Dr. Yehiel Tschlenov on February 1st, 1918. Shown in his estate on Mt. Carmel with his portrait.
Sandro Tonini (31 Jul 03)

Iraq, general revenue, either 1969 issue (22.5x27 mm) or 1972/87 (23.5x29 mm). See Ross/Powell "The new stamps of Iraq" (1998), #315 or #322.
Rolf Kirchberg (12 Sep 00)

This stamp is a documentary stamp from Thailand. Issued 1957-1958. Inscription on top: THAI GOVERNMENT. Inscription at foot: WE SUPPORT PUBLIC CHARITY/FOR/HEALT AND EDUCATION. You can find this stamp in:"The Revenue stamps of Thailand" by Peter Collins. It is stamp D1  the 25 satang .
Jos Oostvogels (27 Dec 99)

#260 - This stamp is an afghani airmail stamp listed by Yvert et Tellier as #A60. Issued in 1964, catalog value 2.50 FF.
Stefano Adinolfi

Egypt, an issue by the Syndicate of the Engineering Profession. Identifiable by the Arab inscriptions, see Felkes, pages 83/85 for more details.
Rolf Kirchberg (12 Sep 00)

260B - Early post-WWII charity labels from Poland. "Liga Morska" is "Maritime League".
Jay Carrigan

260C - Early post-WWII charity labels from Poland. "Pomoc Zimova" is "Winter Aid".
Jay Carrigan