OLD:Form 400
      M400     
      M250R   
      M250     
      M400A1   
      M400A2      
      M-1000   
      FORM 109 

NEW:M400R2   
      M400R3   
      M400A3   
      SA-201   
      M250A2   
      M250R2       
      M400A1(NEW)   
      M400A2(NEW)   

Hmmm. you seem to have soem confused:
1960's
M-400
M-250R
M-1000

1970's
M-400
M-400A
M-250R
M-250A
M-1000

1980's
M-400R2
M-400A2
M-1000
M-250R2
M-250A2
M-150 (1980-1985)*

Early 90's
M-400R2
M-400A2
M-250R2
M-250A2

Later 90's to present
M-400 (1997+)
M-400A (1997+)
M-250R2
M-250A2

* Was renamed as the M-250A2 in 1986

Hope this helps.

Thanks for letting me know!!!  I dont know all the exact years for all GE lights.

no problem. i'm learning new stuff every day!