Re. "but an odd roll / protection cage that may not be original?"
We had a Petrol paraffin 35 at work (from new) that had a loader fitted. At the time the owners ran an orchard and after a large stump bounced from the muck fork onto the bonnet above the grill then onto the steering wheel before missing the driver.... the tractor was fitted with a very similar roll cage. slight diff. mountings (front legs onto a channel that ran under the g/box) There was a plate riveted to off side rear brace plate stating for mf35 and mf35x plus other details etc.
Gerry