It would be interesting to see the certificate of authenticity, however I myself have never heard of any other certificates for Brazilian Pumas to compare its "authenticity" too.
The car may be an authentic copy of a Beck 550 Spyder, but built by which Puma? There were a few Puma kits cars made in Italy which were totally different from the Brazilian Pumas. Ford also made a Puma. Brazil also had shops that did tuner mods to Pumas and some had Puma in their name i.e. PUMAKIT.
Is it possible the certificate was primarily used with a known manufacturers name to aid in registering?