Spain 1929 "Exposicion Internacional" Postal Tax Stamps

My 1971 era Scott International album has a page for these stamps and I have several different ones, all 5c denominations, in different colors.
However, my 2015 Scott Classic catalog nor my Stanley Gibbons Portugal & Spain catalog lists them. The Scott Classic section for Spanish Postal Tax stamps starts with RA11 (1937) so I assume that my stamps fell in the missing range of RA1-RA10. Does anyone know when and why these stamps are no longer listed?

Rod222--Thanks for the post. Those are the exact stamps I am asking about. Do you know what year they were deleted? Also, what were the previous Scott numbers for these?

No I do not, Antman.
They are listed in "Catalago Unificado de sellos"
Espana, Europa, Cept.
Edifil Catalogue

Under Barcelona
There are about 4 pages of them.

1929 covered here example
Barcelona
Obligatory Tax Stamps

Note: I think some have control numbers on the back, others do not.

Unlisted Scott.
Possible Postal Tax Stamps?
1940
Franco pro Tuberculosis Cinderellas.

Hopefully usefull info.

As mentioned in a(slightly older) Michel catalogue.

Stamps had to be used on mail within Spain from 22.Dec.1940 till 3.Jan.1941.

The 27 I and 28 I are stamps without the Lorraine double cross.

Kind regards, Johan.

Obligatory use and surtax (in theory, for tuberculose. But, by then...Who kows!) on letter from December 22nd 1940 to January 3rd 1941.

They are listed on "Edifil Unificado" with numbers 936 (violet, regular mail) and 939 (rose, airmail). There are also two "semipostals" as our American friends call them: 937 20 cts + 5 cts green and 938 40 cts + 10 cts blue. You can get the whole mint set for about 2.5 €.

By the way, they're not considered "back of the book" but regular stamps.

Thank you very much Johan, Cursus.
Great Information.
Sorted.
My apologies to Scott Catalogue.
Duly Listed and spots allocated in Steiner

See B123, B124, RA15, and RAC1. (Scott type SP23)