Robert DLUZNIEWSKI
All of these un centavo coins have an incurse writing on the obverse shield while my 1982 has it oposite.
That's not completely correct. The 1 centavo 1981 also has raised writing on the shield:

KM# 275 has 5 subnumbers and the 1 centavo 1981 and 1982 are KM# 275.4
The reason the writing on the shield isn't mentioned in the catalog is because there are so many small differences between the subnumbers not all of them are mentioned. The most important is the KM# 275.4 is the only subtype with outlined coat of arms. But of course, the raised lettering on the shield in stead of incuse lettering is also very noticeable. You can make a change request to add this to the description of the KM# 275.4:
“KM# 275.4 - Outlined coat. Smaller portrait, date, and letters. Date with dots.” At the same time, change “coat” into “coat of arms” so people don't search for a difference in the coat Bartolomé de las Casas is wearing.