The one from Galicia (the round) and the one from Castilla & Leon. Individually numbered and made by the same people that make the ones you see on your walk.
If possible, try to obtain your credential before beginning your Camino. After that, to obtain your carimbos, look four the bombeiros, even to find a bed.
If you need something else, please tell me. May be I can help you. But I can't promise anything ...
I looked at this myself once and it can be done though there are no albergues as such in the South. I did find a cycle company which ran a tour from Lisbon to the Algarve whose route I was going to use but I canot find it at the moment.
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