The fronts are not Princess Calipers, I have a set of those in the junk box and just had a look, the princess calipers have 2 hydraulic hose entrys and the bleed nipples are between the pistons.
They could be Jaguar as JacMac suggested, as the Jag IRS had solid rear discs. The other thing the rears could be is Renault 5 or Fiat 12x series as they too had solid discs.