I can confirm after looking through the 2 foot high pile of paper work that was supplied with her that she is a L1210, I have forgot the drawing number but she is classed as a bridging crane rated at 10 tons.
The paperwork starts from the factory delivery note in 1958 to her last service in 2004, there is every service sheet, insurance certificate, list of faults and parts used etc etc all the way through her life, at the end she was only doing 8 miles between services.
In 1996 she had a fancy lift computer fitted and the new engine in 1990 cost £1250 +vat, the last part to be fitted was a number plate lamp at a cost of 40p.
Had good fun with her to day as we got the crane engine fired up and ran the crane, however a blown fuse in the computer had us confused for a while as some crane functions would not operate and some would.
Is the steering supposed to be very, very heavy as you can just about turn the steering wheel. All the pedals are over to the left with the clutch more or less in front of the steering column, so as you say makes it very akward to drive.