In addition to the Scott Classics Catalog, I find the easiest ID guide is a Scott catalog contemporaneous with the album because it will most closely match up with what you see on the album page. However, finding a catalog from the early 40s in a library I would guess to be difficult although they do come up fairly often on
ebay, etc.
Here is a list of some of the name changes. Hopefully it will save you a little time. You've already discovered, no doubt, that in the pre-1970 Internationals some of the countries were out of strict alphabetical sequence. I've noted the locations in some cases but Scott was always tinkering with these albums, so your mileage may vary.
NAME OF COUNTRY IN 2007 SCOTT CLASSIC ==> NAME OF COUNTRY IN THE SCOTT 1943/7 INTERNATIONAL
Austria Lombardy-Venetia ==> Lombardy-Venetia
Belarus [not in Classic Catalog] ==> White Russia
Belgian Congo ==> Congo
China--Offices in Tibet ==> China Offices Abroad (1911)
China--Provinces--Manchuria ==> China Offices Abroad (1929)
China--Provinces--Sinkiang ==> China Offices Abroad (1915-20, 1929)
China--Provinces--Yunnan ==> China Offices Abroad (1925)
China--Shanghai ==> Shanghai
East Africa and Uganda Protectorates ==> East Africa and Uganda (after Cuba)
Ethiopia ==> Abyssinia
French Morocco ==> France--Offices in Morocco (after Offices in Zanzibar)
German States--Baden ==> Baden
German States--Bavaria ==> Bavaria (before Batum)
German States--Bergedorf ==> Bergedorf (on same page as Baden)
German States--Bremen ==> Bremen (on same page as Baden)
German States--Brunswick ==> Brunswick (on same page as Baden)
German States--Hamburg ==> Hamburg
German States--Hanover ==> Hanover (on same page as Hamburg)
German States--Lubeck ==> Lubeck
German States--Mecklenburg-Schwerin ==> Mecklenburg Schwerin (after Memel)
German States--Mecklenburg-Strelitz ==> Mecklenburg Strelitz (before Mexico)
German States--Oldenburg ==> Oldenburg (after Oltre Giuba)
German States--Prussia ==> Prussia (before Penrhyn Island)
German States--Saxony ==> Saxony
German States--Schleswig-Holstein ==> Schleswig (before Saxony)
German States--Thurn and Taxis--North German Confederation ==> Germany--Postal Service of Princes of Thurn and Taxis--North German Postal District
German States--Thurn and Taxis--Northern District ==> Germany--Postal Service of Princes of Thurn and Taxis--Northern States
German States--Thurn and Taxis--Southern District ==> Germany--Postal Service of Princes of Thurn and Taxis--Southern States
German States--Thurn and Taxis--Wurttemberg ==> Wurttemberg
Iran ==> Persia
Ireland ==> Irish Free State (before Iraq)
Italian Offices Abroad--Aegean Islands (Dodecanese) ==> Italy--Aegean Islands
Italian Offices Abroad--Aegean Islands--Calchi ==> Italy--Occupation Stamps--Karki
Italian Offices Abroad--Aegean Islands--Calino ==> Italy--Occupation Stamps--Calino
Italian Offices Abroad--Aegean Islands--Caso ==> Italy--Occupation Stamps--Caso
Italian Offices Abroad--Aegean Islands--Coo ==> Italy--Occupation Stamps--Coo
Italian Offices Abroad--Aegean Islands--Lero ==> Italy--Occupation Stamps--Lero
Italian Offices Abroad--Aegean Islands--Nisiro ==> Italy--Occupation Stamps--Nisiro
Italian Offices Abroad--Aegean Islands--Patmo ==> Italy--Occupation Stamps--Patmos
Italian Offices Abroad--Aegean Islands--Piscopi ==> Italy--Occupation Stamps--Piscopi
Italian Offices Abroad--Aegean Islands--Rhodes ==> Italy--Rhodes
Italian Offices Abroad--Aegean Islands--Scarpanto ==> Italy--Occupation Stamps--Scarpanto**
Italian Offices Abroad--Aegean Islands--Simi ==> Italy--Occupation Stamps--Simi**
Italian Offices Abroad--Aegean Islands--Stampalia ==> Italy--Occupation Stamps--Stampalia**
Italian States--Modena ==> Modena (after Mexico)
Italian States--Parma ==> Parma
Italian States--Romagna ==> Romagna (before Queensland)
Italian States--Roman States ==> Roman States
Italian States--Sardinia ==> Sardinia
Italian States--Tuscany ==> Tuscany
Italian States--Two Sicilies ==> Two Sicilies
Jordan ==> Trans-Jordan
Korea ==> Corea
Malaya ==> Straits Settlements--Protected States--Federated Malay States
Malaya--Johore ==> Straits Settlements--Johore
Malaya--Kedah ==> Straits Settlements--Kedah
Malaya--Kelantan ==> Straits Settlements--Kelantan
Malaya--Negri Sembilan ==> Straits Settlements--Negri Sembilan
Malaya--Pahang ==> Straits Settlements--Pahang
Malaya--Perak ==> Straits Settlements--Perak
Malaya--Selangor ==> Straits Settlements--Selangor
Malaya--Sungei Ujong ==> Straits Settlements--Sungei Ujong
Malaya--Trengganu ==> Straits Settlements--Trengganu
Netherlands Antilles ==> Curacao
Netherlands Indies ==> Dutch Indies
Portuguese Guinea ==> Guinea
Puerto Rico ==> Porto Rico
Ruanda-Urundi ==> Belgian East Africa
Saudi Arabia ==> Hejaz
Saudi Arabia--Nejdi Administration of Hejaz ==> Nejd
Slovakia SEE ALSO Czech 255-256 ==> Czechoslovakia--Slovakia--German Protectorate
Solomon Islands ==> British Solomon Islands (after British East Africa)
South Africa ==> Union of South Africa
Spanish Morocco ==> Spain--Offices in Morocco
Spanish Morocco--Tangier ==> Spain--Offices in Morocco--…Tangier (after Spanish Guinea)
Spanish Sahara ==> Spanish Western Sahara
Thailand ==> Siam
Turkey--Military Stamps--For the Army in Thessaly ==> Turkey--Offices in Thessaly
Ubangi-Shari ==> Ubangi
Yugoslavia--Croatia-Slavonia ==> Jugoslavia--Slovenia-Carniola
BOB