You'll probably kick yourself, but Dyson do a fixed price service on a DC07, with all parts, for £65.
If the motor has failed, the chances are that you will also need a post-motor filter (under the cover where the dust canister sits) as well as a motor. (Check the old flter: Black and ragged=new one.)
The cost of a motor, filter and shipping would be getting on for £55-60, so for £5-£10, it isn't worth getting your tools out, especially as the Dyson job is guaranteed for a year.
Our motor failed a few months back and I searched for a solution, as well as asking the question for the umpeenth time, and found the info about Dyson servicing.
Put in the order and within five days had the motor and filter supplied and fitted, PLUS a new clutch ('cos the old one "looked a bit worn") AND a new cyclone (Safety upgrade, I think) AND a new pre-motor flter and carrier.
In short, about £110 of stuff supplied and fitted for £65.
John
July 2008