This is a very interesting concept. If we have the UK spend more time developing a Caribbean customs union and gradually moving towards federalism and Guyana is incorporated, Forbes sounds like he would be the perfect candidate for the Federation's first prime minister.
Doubt he would be the first. He would have been 35 in 1958 and I get the impression that many politicians in the Caribbean don't become leaders until they are past the age of 40, although looking through Guyana's list of leaders I see that Burnham's chief rival (Chedi Jagan) was 35 when he became chief minister of British Guiana, but that might be more of an exception. Forbes could be the second, third, or more likely the fourth if Forbes brought British Guiana into a federation in 1964 and then maybe ran for election in 1968 (with that election being won by the DLP instead of the WIFLP to which Burnham would like have joined) before leading his federal party to victory in 1973 or 1978 (probably after 1973 if Eric Williams leads the party by then and decides to retire around 1977 and handing over the prime-ministership and leadership of the party to Burnham).
Roughly it could go something like this:
1. Norman Manley 1958-1968 WIFLP
2. Errol Barrow 1968-1973 or 1978 DLP (lead the Barbadian DLP in government in Barbados until 1976)
3. Eric Williams 1973-1977 or 1973-1980 or 1978-1980 WIFLP (lead the local Trinidadian constituent of what was the WIFLP and was prime minister of Trinidad until his death in 1980, so he could either win in 1973 or 1978 and then either retire in 1977 or die in 1980)
4. Forbes Burnham 1977-1983 or 1985 or 1980-1983 or 1980-1985 (if he wins a second term but then dies in 1985) WIFLP
5. Who knows? Probably someone from the DLP or some other party that might have been founded and wrested opposition from the DLP. At some point though I expect a woman would become prime minister. Maybe even that lady from.....Dominica, Eugenia Charles...probably in the opposition camp in the early 1980s. I would also expect that at some point after the 1970s someone of East Indian descent would become prime minister.
In any event this would cause a lot of butterflies:
- No Jonestown. Without Guyana being dirt-poor and thus easily exploited by those waving cash along with immigration being controlled at a federal level (with the less socialist DLP in power in the 1970s maybe) Jim Jones and his followers would not have found Guyana so favourable and might have gone elsewhere...maybe to Canada (one of the original options) or maybe to Suriname or in Central America somewhere (Costa Rica, Panama, Guatemala, Honduras, El Salvador, Nicaragua). Maybe even Colombia.
- No Operation Urgent Fury. The coup in Grenada (if not butterflied away by 20 years of different economic and political development) would have been put down by federal forces (police and military).