There is a massive errata for LGA to be found on grognard.com. It is listed under "La Grande Armee, Publisher: SPI" even though TSR is the publisher.
The 1972 SPI game "La Grande Armée" is not the same game at all but on grognard.com they mix them. On grognard. com only the errata and Chris Perleberg's variant (also on BGG) are to be used with TSR's game.