I'm not 100% sure how you would phrase it in English, but something along these lines, I think. "Del volante" probably means "column-mounted", in fact.

Anyway, "inversor" is what MF call the "shuttle" in Spanish. I got hold of this by comparing the English and Spanish versions of the brochure for another tractor, the MF 7600.
Spanish here: http://read.uberflip.com/i/338546/56
English here: http://www.masseyferguson.com/EMEA/ZA/static/documents/MF760...

It would take to long to copy out all the instances. Here are the first couple, on p. 23 (both versions):

"Reverse shuttle progressivity adjustment"
"Ajuste de la progresividad del inversor de marcha atrás".

"Power Control lever
The left-hand Power Control lever provides convenient and straightforward operation. From here you can operate forward/reverse shuttle, powershift and range changes and fingertip de-clutching [...]"
"Palanca Power Control
La palanca Power Control situada a la izquierda ofrece un funcionamiento cómodo e intuitivo. Sirve para accionar el inversor de marcha adelante/atrás, powershift y cambios de gama y desembragado con un solo dedo [...]".

And so on. On this model the shuttle's a button, judging from the pictures on pp. 38 and 39, but it can be a lever.

Plenty of refs. to the shuttle on a tractor:

"the forward/reverse shuttle lever is mounted to the left of the steering wheel"
http://www.tractordata.com/news/2004/04/massey-5400-series-t...