new to Micra K10

inherited a micra 1.2 auto MK1 .sadly very high blow by as cel's 3/4 scuffed after over heating. looking up cost of rebore .new pistons .rings .gaskets etc simply not worth investment or time. checking out for used engines isn't so easy as 1.2 K10 units are few and far between it seems. though have seen a lot of K12 units not exactly cheap but wont break bank. question I have a knowing naff all about these cars is the engine basically that same but just improved eg fuel injection? as if so would it be feasible to strip a K12 and use block and head with original list such as Carb. gearbox .starter etc.