I just received an email from the owner of a '70 SS-454 (LS5). It appears that he has a genuine car, built in Canada, with paint code "43" ("Lime Green" metallic), which is a color not offered on Chevelles until the 1971 model year.
This car also has the option "D99". My books do not list this code, but I suspect it is a special-order color option, available only on Canadian-built cars.
The owner also claims to have the GM of Canada documentation showing the paint color 43.
Here are the codes, as emailed to me:
70 13637 OS559173
TR 795 4343
Chevrolet Malibu 2-door coupe
Oshawa , Canada plant
body sequence number, not related to VIN
"Dark Green" vinyl bench seat interior
"Lime Green Metallic" upper & lower body color
built the second week of April (1970)
Heavy duty Muncie close-ratio 4-speed ("Rockcrusher")
?? Could be the special paint order.
Team Chevelle Gold Member #11, ACES #701
Author of the GMC Sprint, El Camino, and '68-'72 SS Authentication pages.
See my GM A-body fleet at: