wouldn't they have enough 15" turrets to re-arm Tiger, while re-building her and modernizing the ship?
You also cant do that (at least till treaty's collapse)
WNT 1923-1936
"(d) No retained capital ships or aircraft-carriers shall be reconstructed except for the purpose of providing means of defence against air and submarine attack, and subject to the following rules: the Contracting Powers may, for that purpose, equip existing tonnage with bulge or blister or anti-air attack deck protection, providing the increase of displacement thus effected does not exceed 3,000 tons (3,048 metric tons) displacement for each ship. No alterations in side armour, in calibre, number or general type of mounting of main armament shall be permitted......."
2 LNT till at least April 37
"(2) No capital ship shall carry a gun with a calibre exceeding 14 in."
So you cant rebuild her till very late and by that point its to late and you could anyway build a Vanguard.....