Hi Tony,
And thanks for that. Indeed, it is cab 11. Mea culpa. Being in a hurry today I dind't spot the bolted bonnet (hood). Shame on me, the bolts behind the radiator shell are clearly visible on the picture!
Most probably that "IS" is typo or OCR error but it suggest number "15".
However, it is still better than
THIS:
Cheers!