Answer:
There were four types of Pimms No 1 No 2 No 3 and No 4
No 1 was for gin
No 2 was for brandy
No 3 was for whiskey
No 4 was for rum
it is rare to find 2,3, and 4 nowadays
This is not true. There were 6 types of Pimm's. Pimm's No 1 Cup (Gin) Pimm's No 2 (Scotch) Pimm's No 3 (Brandy) Pimm's No 4 (Rum) Pimm's No 5 (Rye Whiskey) and finally Pimm's No 6 (Vodka). Today only 3 can be found. No 1, No 3 (as Pimm's Winter Cup) and No 6. And just to be utra nerdy it's spelt Pimm's (with an apostrophe) after James Pimm who used to run a Public House during the mid 1850s in The City of London at Poultry.