The Mobile Excavator was a combination of previous models to create a toy with good play value but which as a real vehicle would probably not have been viable!

The casting of the cab and chassis were indentical to the AEC Sunderland truck which Benbros had used for several former models but a small strengthening panel was added above the rear axle presumably to cope with the weight of the excavator body. Like the other Sunderland lorries, cab. chassis and base were always painted red. Under the chassis 'Benbros Qualitoy' and 'Made in England' were cast. 

Most of the Mobile Excavators had '6-bolt' metal wheels coloured red, yellow, or dark-blue, painted on the outside only, but some models were later fitted with unpainted metal wheels with large hub-covers similar to those on Zebra Toys. Finally, Benbros switched to yellow or red plastic wheels using the same '6-bolt' design. All types of wheel were fitted with lightly treaded black rubber tyres.

Like the Mobile Crane, the red & yellow Ruston-Bucyrus Excavator was centrally fixed to a platform which covered the entire chassis and which was held in place by a tab behind the cab and a rivet at the rear through the chassis. For the Excavator itself, Benbros used the second type with unpainted metal handles and a pin securing the arm and bucket to the body. '10-RB' decals as usual were added to both sides and 'Ruston Bucyrus' was cast at the back.

The lifting arms, bucket and lower flap were all painted dark green and were operated from the handles in the body using strings attached to the jib and bucket. The handles seem to have been fitted randomly and can be found on each side of the body or both on one side, usually the right-hand one.

The Mobile Excavator shared a red & yellow box with the Mobile Crane which had illustrations and names of the two models on opposite sides. On one end-flap a blank panel was left for the model details to be added, in this case 'M. Excavator'.

The Mobile Excavator is a scarce model even in playworn condition, and mint boxed examples are hard to find and carry a premium value.