Olivetti Praxis 48 serial numbers

Dingwerth gives the following numbers in his "Schreibmaschinen-Lexikon für die Zeit ab 1940". Dingwerth states that the first year of manufacture is sometimes not precise.

1964-01-01      5,000,001

1965  

1966-01-01      5,034,216

1967

1968

1969-??-??       5,180,000

1970-??-??       5,227,000

1971-??-??       5,283,000

Carlo Torchio gives in his "Olivetti. Macchine per Scrivere Meccaniche" the following numbers. 

1965-01-01      5,000,001

1965-12-31      5,034,215

1966

1967

1968

1969-12-31       5,180,000

1970-12-31       5,227,000

1971-12-31       5,283,000

1972-12-31       5,333,117

1973-01-01       5,333,118

The Typewriter Database gives us the following informations:

1969-??-??        5,180,000

1970-??-??        5,227,000

1971-??-??        5,283,000

1972-??-??        5,333,117

1973-??-??        5,404,669

1974-??-??        5,447,463

I think Dingwerth is wrong with 1964. Torchio does his research in the Olivetti archive, so he is probably more precise with the year of introduction. I've reconstructed now an age list (no estimations, only from the above informations). The numbers for 1969–1971 are probably not precise, they have "too many zeros" ("glatte Zahlen" in German).

1965      5,000,001 – 5,034,215

1966      5,034,216 – 

1967

1968

1969                       – ca. 5,180,000

1970                       – ca. 5,227,000

1971                       – ca. 5,283,000

1972                       – 5,333,117

1973      5,333,118 – 5,404,669

1974      5,404,670 – 5,447,463

I hope this is helpful. Please comment if you have more information or if you have an Olivetti Praxis 48 with bill of sales or guarantee card with known year. Or you just know in what year you bought it if you bought it brand new.