I bought this coin fairly recently, a dealer had sent it in to PCGS as a 'mystery Cu-Ni strike'. I did a bit of digging, with the Royal Canadian Mint reports from 1978 (reporting production from 1977) and of course, a Krause catalogue for confirmation of the foreign coin specifications. Turns out, there was only one cupro-nickel planchet that the Royal Canadian Mint produced in 1977. While the Royal Canadian Mint did commonly strike coins for other countries, they also produced planchets to order. This is a Canadian 1977 1-cent struck on a Cu-Ni planchet ordered by Portugal for striking 2 1/2 escudos coins (KM #590). According to RCM reports, it weighs 3.55 grams and 32,215,558 of these planchets were produced. Of course, not all were delivered, because I know of at least one that found its way into Canadian decimal production strikes... :smile
I have a question, following this up, to the error collectors here: I would like to send this coin back to PCGS, and have them put the identified planchet (by country and denomination) on the label. Will I be charged the full cost of an error submission for asking for that??