Besides local English, there are plenty of straight borrows from American, Jamaican, and Hindi (probably some through older cant, I'd guess).

For example, this "RAAAAHS" is just short for Jamaican 'ras-claat' (literally, a cloth soiled with body excretions), though in this use it is just like exclaiming "Hot Dang!"

Pukka is the old British-in-India word, from Hindi "proper" (fully-cooked)

Deekin' must be from the Romany (ultimately Indo-Aryan, cf. Hindi 'dekh') 'dik' - to look/see.