1. Orange River Colony (a.k.a. Orange Free State) Sc#3 was issued 15 years
before Sc#1, with Sc#2 (½ d orange) even later in 1897.
2. Oldenburg SG 1 is a
½grote black on green which Scott dates as 1859 and numbers Sc5. As this is
priced at £1,000 mint and used, I'm happy to go with Sc#1.
3. Orchha Sc1 was issued after Sc2.