MEngr, since the emissions standards are most likely not quite a strict in Kenya as in California [or the rest of the USA, for that matter] who and how the engine is rebuilt may not be quite a a strong requirement for the original poster as it is for us.
AND
while you may have some information I do not, as far as I know, while the emissions controls have been updated and fine tuned for forklift manufacturers and applications, the engine block and head itself has not been going through changes each year since it's introduction (or can you point me to some information where I can learn about the changes to the head and block, like a parts book with different PN [for the block, pistons head etc...] for different years?)