Easiest way to see the difference between 10 centavos 1986 KM#277.4 and KM#277.5:
Reverse: KM#277.4 has plain field around monolith while KM#277.5 has bushy field around monolith
Obverse: KM#277.5 has incuse lettering on shield while KM#277.4 has lettering in relief on shield
Change request is made.