Parkway2
i saw the images you sent me

that one light indicator right in front of the directional switch as you said does not show in the manual, from the looks of it it may be some addon indicator put on the machine after production, it may even me some aftermarket system, i've never seen anything like that on any combi GT units i've worked on.
mohamed_m suggested an engine management light, i doubt that is what it is as it is not marked with any pictogram like the ones in the instrument cluster are marked and i wouldn't think combi would throw on an additional indicator light without any markings or explanation in the manual about it. But don't hold me to that as i've been wrong before ;o)

you could remove the cover and trace out the wiring and see where it leads to, that might give you an idea of what it's function might be.

one other option is to send in a request to combilift and ask them
info @ combilift.com (remove the spaces i added to the email address to make it work)
maybe they could give you some insight as well.

i had a thought to verify my doubts about it being an MIL light, you could disconnect an O2 sensor or some other sensor and run the machine and make it trigger the error and see if the light on the dash lights up.
just a thought ;o)