Here's a list of British Prime Ministers, with some speculations. The only differences with OTL's list occur during and after the Cambpell-Bannerman Premiership. IOTL he died in 1908, yet in TTL he's alive in 1909. Everythings the same before than, even after the POD, since butterflies havnt reached over the pond yet so to speak. Also, everyone after Curzon is fictional, in keeping with TTL's rules.
King George I (1714-1727) and George II (1727-1760)
Sir Robert Walpole (Whig) (1721-1730, 1730-1742)
Spencer Compton, 1st Earl of Wilmington (Whig) (1742-1743) †
Henry Pelham (Whig) (1743-1754) †
Thomas Pelham-Holles, 1st Duke of Newcastle (Whig) (1754-1756)
William Cavendish, 4th Duke of Devonshire (Whig) (1756-1757)
Thomas Pelham-Holles, 1st Duke of Newcastle (Whig) (1757-1762)
King George III (1760-1820)
John Stuart, 3rd Earl of Bute (Tory) (1762-1763)
George Grenville (Whig-Grenvillite) (1763-1765)
Charles Watson-Wentworth, 2nd Marquess of Rockingham (Whig-Rockingham) (1765-1766)
William Pitt, 1st Earl of Chatham (Whig-Chathamite) (1766-1768)
Augustus FitzRoy, 3rd Duke of Grafton (Whig-Chathamite) (1768-1770)
Frederick North, Lord North (Tory) (1770-1782)
Charles Watson-Wentworth, 2nd Marquess of Rockingham (Whig-Rockingham (1782) †
William Petty, 2nd Earl of Shelburne (1783) (Whig-Chathamite)
William Cavendish-Bentinck, 3rd Duke of Portland (Whig) (1783)
William Pitt the Younger (Tory-Pittite) (1783-1801)
Henry Addington (Tory-Pittite) (1801-1804)
William Pitt the Younger (Tory-Pittite) (1804-1806) †
William Grenville, 1st Baron Grenville (Whig) (1806-1807)
William Cavendish-Bentinck, 3rd Duke of Portland (nominally Tory) (1807-1809)
Spencer Perceval (Tory) (1809-1812) ††
Robert Jenkinson, 2nd Earl of Liverpool (Tory) (1812-1827)
King George IV (1820-1830)
George Canning (Tory-Channingite) (1827) †
Frederick John Robinson, 1st Viscount Goderich (Tory-Channingite) (1827-1828)
Arthur Wellesley, 1st Duke of Wellington (Tory) (1828-1830)
King William IV (1830-1837)
Charles Grey, 2nd Earl Grey (Whig) (1830-1834)
William Lamb, 2nd Viscount Melbourne (Whig) (1834)
Arthur Wellesley, 1st Duke of Wellington (Tory) (1834)
Sir Robert Peel (Conservative) (1834-1835)
William Lamb, 2nd Viscount Melbourne (Whig) (1835-1841)
Queen Victoria (1837-1902)
Sir Robert Peel (Conservative) (1841-1846)
Lord John Russell (Whig) (1846-1852)
Edward Smith-Stanley, 14th Earl of Derby (Conservative) (1852)
George Hamilton-Gordon, 4th Earl of Aberdeen (Peelite) (1852-1855)
Henry John Temple, 3rd Viscount Palmerston (Whig) (1855-1858)
Edward Smith-Stanley, 14th Earl of Derby (Conservative) (1858-1859)
Henry John Temple, 3rd Viscount Palmerston (Liberal) (1859-1865) †
John Russell, 1st Earl Russell (Liberal) (1865-1866)
Edward Smith-Stanley, 14th Earl of Derby (Conservative) (1866-1868)
Benjamin Disraeli (Conservative) (1868)
William Ewart Gladstone (Liberal) (1868-1874)
Benjamin Disraeli (Conservative) (1874-1880)
William Ewart Gladstone (Liberal) (1880-1885)
Robert Gascoyne-Cecil, 3rd Marquess of Salisbury (Conservative) (1885-1886)
William Ewart Gladstone (Liberal) (1886)
Robert Gascoyne-Cecil, 3rd Marquess of Salisbury (Conservative) (1886-1892)
Archibald Primrose, 5th Earl of Rosebery (Liberal) (1892-1895)
Robert Gascoyne-Cecil, 3rd Marquess of Salisbury (Conservative) (1895-1902)
Edward VIII (1902-1913)
Arthur Balfour (Conservative) (1902-1905)
Sir Henry Campbell-Bannerman (Liberal) (1905-1911)
Herbert Henry Asquith (Liberal) (1911-1916)
Victor (1913-1953)
David Lloyd George (Liberal) (1916-1924)
George Curzon, 1st Marquess Curzon of Kedleston (Conservative) (1924-1925) †
Reginald Hackett (Conservative) (1925-1931)
Andrew David Hobbes (Liberal) (1933-1935)
Reginald Hackett (Conservative) (1935-1938)
Isaac Pickering (Liberal) (1938-1952)
Sir Ryan Baxter (Conservative) (1952- )
George V (1953- )
† = Died in Office
†† = Assassinated