"FG" Serial Number Prefix ? MF 135 UK Model

[GeorgiaYankee]

Can any one tell me what the "FG" prefix means in front of the serial number on a MF 135 UK Model Tractor represents?

 

[Wagtail]

The best that I can come up with is that the "F" means that it's 'multi-power'.

The "G" can refer to the type of hydraulic pump fitted... which may also refer to the tractor being made for export to the US market.