Scotland disinheritance from Will

[Elscorcho]

Myself and my brother have been left out of our dad’s Will. His other son is the only person*named on the Will. By Scots law am I right that me and my brother can claim half of the moveable estate and share that between the two of us? The other son named on the Will can only claim from the Will which is the other free half of the moveable estate? It says by law that he cannot claim from both the Will and the legal rights. Therefore he gets 50% overall, I get 25% and my brother gets 25%... is this correct? There is only moveable estate to inherit and our dad died without a spouse/civil partner.