That is quite possible and happens very often in catalogs.
The export catalogs I have for the 308 and 309 were printed one month apart only : 10/73 (L-308) and 11/73 (L-309). The L-309 german version was printed alongwith the english version, but all three were printed in Japan.
If the THD on the latter version is correct (@75W), the weight is the same 12,5kg...
Having found so far no other source(s), I did "quote as published" - but forgot I had the german version to double-check. Too many catalogs in my head !
I guess somebody at marketing took a shortcut and just changed the main differences (power rating and features/functions) and let the rest remain exactly equivalent for the english/worldwide printing.
@ THD specs corrected - thanks !