I wouldn't call the grips 'Portugese' but rather 'cheap repro'
There have been a number of examples coming onto the market since the 1990s that all had some sort of cheaply made repro-grips on them. This lends to the idea that some surplus reseller got a buch of P08s either without original grips or with badly worn/damaged grips and decided to have some quick repros made in order to create a 'complete P08' for resale.
This is also the main reason for the Russian surplus theory. Russia was always very good in producing cheap looking plastic crap